I don't believe this anymore.
After 4 years of trying to follow this advice, and building 4 different web applications that were things "I wish someone would make." I've given up on following PGs advice. Perhaps I'm an anomaly, but I'm fairly sure I'm not as there are so many startups out there that all try to solve the same handful of problems, and fail.
Most of us are developers, and we have a set number of 'tasks' that seem like they should be something you could build a business out of and so we all try to do them. Task Management, Project Management, Time Tracking, Social communication, etc. There are obviously winners in this space but they are established, and it is extremely difficult for a small group of developers to come along and decide to 'solve' one of those problems.
Maybe I'm just not interesting enough, I'll admit that is possible, but I've found much greater success by building applications that people tell me they want, and pay me to build.
I also don't have a billion dollar startup, so don't listen to me, but I couldn't let another article get by with espousing the virtues of just 'building what you like' without saying something.
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