If you don't journal your ideas and thoughts then I suggest you create a GitHub repository and begin journalling in markdown for minimal friction.

Then do it everyday. You'll think of something interesting, or a problem that needs solving, or pain you see in the world around you.

You have criteria for what you find interesting, you need to dig deep inside yourself to unearth what you're keeping bottled up inspiration.

Then revisit your journal frequently, add to it, remix it and begin sideprojects.

See my profile for my journal, I have 450+ software idea and startup idea entries.