Nobody has any use from a 80% finished project (so not finished at all) except it was a lot of time and money to get to that point. Oh boy I need to make progress on about 500 different projects to get them to a useful stage.

Also very important lesson: Dont have your anxiety take over when facing the "omg I have a 6 digit number of things on my 2do list" because you can't say no to the "awesome" ideas you have.

Also: I have made a rule for myself that prevents me from starting/working on a side project when I have important deadlines on main projects