Do your best projects usually start as secret side tools?

Trying to guess what a generic market wants always leads to the most boring software. Whenever I try to build something based on market research I end up overcomplicating every single feature just to please a hypothetical user who doesn't even exist.

But the tiny scripts I hack together on a Sunday just to fix my own messy workflow always turn out to be the stuff people actually want to use. Building purely out of personal frustration keeps things so simple.

Do you usually release your internal side tools publicly or keep them private?