I had a saying years ago, when I really needed to get my shit together: "If I'm stupid enough to think it, I should be smart enough to do it". Now, this is specifically for things that would benefit me but that I didn't want to do, because, y'know... when you're a lazy piece of shit it's easy to continue to be a lazy piece of shit. It's way easier to say 'Oh I'll get to that later' and pack another bowl instead of doing the dishes or taking out something to prep for supper.
When I needed it the most, my little self-made mantra was exactly what I needed to kickstart my efforts. And now, I almost never need it.