I built a lot of apps last year. I approved most of the code and commits that went into them, and a good portion of it I could not explain.
Not "couldn't explain to a junior." Couldn't explain to myself. The tests were green, the diff looked like something I would have written, and I hit approve. If you had stopped me forty minutes later and asked why that function needed a lock, I would have had to go read it again like it was someone else's code.
Which, in a sense, it was. And because most of these were my own projects, there was no second reviewer downstream of me. I was the entire quality gate — and the gate had quietly stopped reading.
I am not going to pretend this is a novel observation. If you read dev.to you have already seen this post four times this spring, and if you read r/ExperiencedDevs you have seen the thread where someone calls themselves "a tourist in their own codebase" and four hundred people say yeah, same. One in five developers in the 2025 Stack Overflow survey picked "I've become less confident in my own problem-solving" as a top frustration with AI tools. The fear is not underreported. It might be the most reported feeling in software right now.
So this isn't a diagnosis post. The diagnosis is done. What I couldn't find anywhere was an honest answer to the next question: every fix anyone proposes for this has the same shape, and that shape is known to fail. Including the one I spent two weeks designing.
