Wow, I'm clearly a minority, but I'd say "NEITHER". The first thing is to find something you like and can be passionate about. Then - work on it. It can be stupid or crazy, that's fine. Go get a horse or hang-glider or a kiln or a 3d printer or a commodore 64 or a guitar or lima beans or astronomy or trolling reddit or...
Don't work on something you don't really care about. No reason to ever do that.
Don't work on nothing at all. It's literally the same thing as working on something you don't care about except less productive.
Everyone can find something interesting to be passionate about. No excuse.