> If I create something, but nobody ever sees it, did I create it at all? Doesn't feel like it.

You have been trained to require external validation for your work. Maybe it's a modern thing with upvotes and twitter and likes and whatnot.

If you create a thing, then you have drawn on your skills, probably improving them. Whether the thing is seen by others is irrelvant. What is relevant is your experience in creating it, and the use of it (whether it has a use, or just has aesthetic value).

Maybe practice by creating something, then destroying it, as if it had never existed. What remains? Memory and skill, both of great value.