The common approach to build tech products is to solve your own problems. I agree. But what if I have 99 problems? We all have tons of problems, and I certainly can't afford to build a solution for everything: how do I go about prioritizing my side-projects?
I believe my never-ending goal in life is to pursue mastery: to be great at what I love doing - not just great at a craft, but at my own craft, at the crossroad of my widely varying interests, to the point of pushing the boundaries of what I am capable of.
Building products becomes a way to solve problems I have in my daily life to support my ultimate goal. A product is an extension of my being, rather than a mere stepping stone to make some money.
This is why I have some doubts when people say we should validate our ideas before making something. It assumes we can answer the question "Can I make money out of this?", but what if I am my own customer? I buy my own solution with my own time to free some more time down the road.
We all love making stuff ourselves. If your neighbor is building himself a house, do you ask him if he already validated his idea? No, because he is the one who is going to have to live in this house, someone else's opinion is irrelevant. The same principle applies to tech products. Worst case: it will only make you stronger.
Indie making is not just an alternative branch of entrepreneurship, it's a way of life where you use your skills and interests to improve your own daily life. You can build things with others, but when the project is at the ideation stage, it should only be about you: what's the one thing about your life you absolutely can't stand anymore?
Take a good look at what you do, how you do it, and why. Question everything. Even the meaning of life itself. Makership is the ultimate freedom to learn and experience new aspects of life. Mastery is a state where our craft is in everything we do. Prioritize the side-project that will significantly improve your day-to-day life, not because you can earn money from it, but because it's bursting out of your very soul.