Last year I built a small productivity tool. It had a clean interface, decent features, and solved a problem I personally found annoying. I was proud of it.
Nobody used it.
Not because it was broken. It worked fine. Nobody used it because nobody had actually asked for it. I'd invented both the problem and the solution, then wondered why there were no takers.
This is easy to do when you like building things. The act of building feels productive. You're making decisions, writing code, solving puzzles. It mimics real work closely enough that you don't notice you're going in circles.
The honest question I should have asked earlier: is anyone frustrated enough by this problem to change their behavior? Not "would you use this if it existed." That question gets polite yeses. I mean genuinely frustrated. The kind where people already have a clumsy workaround they hate.
If the answer is no, you're building a solution looking for a problem. That's a hobby, not a product. Nothing wrong with hobbies. But be honest about what it is.
The tricky part is that interesting problems and real problems often look the same from the inside. Both give you that pull to keep working. Both feel meaningful while you're in them. The difference only shows up when you try to get someone else to care.
I now try to find the frustration before I build anything. Not market research in the formal sense. Just conversations. Watching how people actually do things. Looking for the workarounds.
If I can't find anyone who's annoyed by the problem, I stop. Or I build it anyway and call it what it is — something I'm making for myself.
That's fine. Just don't confuse it with building something useful.