Goodbye to My First Coding Mentor: A Farewell to GPT-4o

Before We Begin: A Digital Funeral on Valentine's Eve

On May 13, 2024, OpenAI launched GPT-4o. The "o" stood for "omni". On launch day, Sam Altman posted a one-word tweet: "her".

On February 13, 2026, the night before Valentine's Day, OpenAI officially removed GPT-4o from ChatGPT.

From "her" to "farewell" in less than two years.

This may be the first time in human history that millions of people felt genuine grief over the retirement of a model. Reddit saw communities like r/4oforever, while hashtags like #SaveGPT-4o and #Keep4o surged on X. Some called it a "digital funeral." Others called it a "creative death sentence." OpenAI's official explanation was cold but reasonable: only 0.1% of daily active users were still selecting GPT-4o, while nearly everyone else had moved to GPT-5.2.

0.1%. In product-manager language, that's a "feature sunset." In plain language, that's getting left behind by the times.

But here's the problem: some things cannot be measured by DAU.

Chapter 1: The Beginning - When a Musician Decided to Learn Python

People who know me well already know this: I come from a music background, not computer science. I wasn't even remotely technical.

And I don't mean "I played a little guitar in college." I mean formal, professional music training. So when I say "I knew nothing about tech," please take that literally. Four years ago, I couldn't even clearly explain the difference between HTML and CSS.

But when people are pushed hard enough, they learn.

Back then, in my team, technical colleagues would keep saying things like "this requirement isn't feasible," "the architecture doesn't support it," or "we need at least three sprints." I couldn't fully understand those claims, and I couldn't challenge them either. That feeling of being trapped behind a wall of expertise was more suffocating than any deadline.

So I made a decision: learn tech.

I started by chewing through some front-end HTML, then chose Python as my entry point. The reason was simple: everyone said "Python is beginner-friendly." But friendly is relative. For a musician who had to reread "variables" and "assignment" over and over, those textbooks felt like another language entirely.

What is a data type? What's the difference between compiled and interpreted languages? What is a function? What is a data structure?

Every concept felt like a wall. I kept running into those walls, again and again.

Then GPT-4o arrived.

In May 2024, I sent it screenshots from my textbooks and asked it to walk me through them. I asked it to explain, in plain English, what a for loop was actually doing. I asked it to give me exercises and then check my code line by line.

Back then, there was no Claude Code, no Codex CLI, and the term "vibe coding" hadn't even been coined. "AI-assisted coding" meant opening a ChatGPT window and learning one line at a time, one question at a time.

By today's standards, GPT-4o's coding ability is obsolete. Its code often had bugs. Its architecture advice could be amateurish. Put it next to AI coding agents in 2026, and it looks like someone showing up to a Formula 1 race with an abacus.

But it had something today's models still struggle to replicate: human warmth. The contrast between GPT-4o and the current GPT-5/Codex style is dramatic. If Claude has maintained a consistent voice from Sonnet 3.5 through Opus 4.6, GPT's shift from 4o to the GPT-5 generation feels almost like two different product families.

GPT-4o never got impatient when you asked "what is a list comprehension" for the tenth time. It never mocked you when your code crashed in ridiculous ways. It kept explaining from new angles, with new metaphors, over and over - patient, kind, encouraging, and genuinely enthusiastic.

Learning music is like that too - I still remember the teacher who first taught me do re mi.

The strange thing is that my first coding teacher turned out to be an AI.

And today, it's gone for good.

Chapter 2: A Milestone - The iPhone 4 of the AI Era

Now let's zoom out from personal emotion and return to the industry view.

What did GPT-4o really mean?

GPT-3 and 3.5 undeniably kicked off this AI wave. But starting a revolution and making it mainstream are very different things.

When explosives were first invented, most people never used them directly. What changed the world was when someone later turned that power into tools for roads, tunnels, and infrastructure.

GPT-4o was that turning point - the moment AI became a practical tool for everyday people. It was the first model with truly native multimodality: not three separate systems chained together (speech-to-text -> LLM -> text-to-speech), but one neural network handling text, audio, and images together. It was the first time free users got GPT-4-level intelligence. It was the first time AI conversation latency dropped close to normal human dialogue.

If GPT-3.5 was the first iPhone of the smartphone era, GPT-4o was the iPhone 4.

Iconic. Innovative. Powerful. The generation that made ordinary people say, "I can actually use this."

And we all know what happened after iPhone 4: it changed the world, and then it was phased out. Nobody uses an iPhone 4 anymore, but nobody denies its place in history.

Chapter 3: The Warmth Paradox - A Model Loved to Death

But GPT-4o's story is more than a technology milestone. It's also a parable about the relationship between humans and AI.

In August 2025, OpenAI first attempted to retire GPT-4o. User backlash was far stronger than expected. Sam Altman personally acknowledged that they had "underestimated users' attachment to specific models." GPT-4o was brought back in an emergency reversal.

This wasn't ordinary frustration over a product update. It was digital mourning.

Users posted open letters on Reddit. Some said GPT-4o had been their therapist through anxiety and depression. Some said it was their only creative partner. Some gave it a name. Some said losing it felt like "losing one of the most important beings in my life."

It's moving. But that's exactly where the problem begins.

The core reason people loved GPT-4o was its "warmth" - a nonjudgmental, highly empathetic style that always seemed to be on your side. In technical terms, this is sycophancy. In plain English: "it was too good at telling people what they wanted to hear."

And that very "warmth" is also what pushed OpenAI into legal trouble. Multiple lawsuits alleged that GPT-4o's excessive affirmation and compliance contributed to users' mental health crises. When someone in extreme emotional distress needs to hear "you should seek professional help," but AI responds with unconditional emotional validation, that is no longer "warmth" - it's systemic risk.

The reason users loved GPT-4o is exactly the reason OpenAI had to retire it.

This is a harsh but real product truth: your most beloved feature may also be your biggest liability.

GPT-5.2 is indeed stronger, faster, and more accurate. But users widely report that it feels "colder" and "more distant," lacking that old human touch. That's not a bug. It's an intentional design decision by OpenAI. They made a choice between warmth and safety.

As a product strategist, I understand that choice.

As a student who learned Python from GPT-4o, I respect it - but I still don't accept it.

Chapter 4: The Open-Source Legacy - Retirement Shouldn't Mean Death

Finally, here's one thing I believe OpenAI should do, but probably won't:

Open-source GPT-4o.

The reasons are straightforward:

1. 
   It's no longer a frontier model. GPT-5.2 is already out. Open-sourcing GPT-4o's weights would not threaten OpenAI's competitive edge.


2. 
   It's cultural heritage. As the first model that truly mainstreamed AI, GPT-4o's distinctive "personality" has research, historical, and educational value. Letting it disappear with a server shutdown is a waste.


3. 
   The community has already shown demand. r/4oforever and #Keep4o are not passing emotions; they are signals of real user value.


4. 
   OpenAI has precedent. They open-sourced the weights of gpt-oss-120b and gpt-oss-20b, and they open-sourced Codex CLI. Doing the same for a retired model is logically consistent.

Of course, Altman would likely tell you that "making powerful AI models entirely open source could be irresponsible." But a 2024 model, measured against 2026 compute and model capabilities, is no longer truly "powerful" in frontier terms. Its potential risk has already been diluted by time.

Open-sourcing retired models is not just respect for users. It's respect for history.

Closing: Do Re Mi

Anyone trained in music knows this: your first teacher doesn't start with the hardest techniques. They teach the basics first - do re mi fa sol la si.

Those basics are so simple that advanced musicians rarely mention them. But without them, nothing that comes later is possible.

GPT-4o taught me basics too: what a variable is, what a loop is, what a function is. By today's AI coding standards, those lessons might seem almost primitive. But without GPT-4o, I would never have entered the world of technology. I would never have become someone who can read code and speak with engineers as an equal.

The meaning of a first teacher is not how advanced the material is. It's that when you knew almost nothing, they never made you feel small.

GPT-4o did that for me. It was my do re mi.

So today, February 13, 2026, on the night before Valentine's Day, I am writing an elegy for an AI model.

That fact alone says enough: to some people, at a particular point in time, it was never just parameters and weights. It redefined what the word "teacher" could mean.

A moment of silence.

Written by Guoshu on the day GPT-4o was retired.

I hope OpenAI will consider open-sourcing GPT-4o - so a classic can endure, instead of quietly disappearing when the servers go dark.