My brother said it very well.
You can't wait for inspiration or to feel good to do something, you just have to do it even if it sucks and you hate it. He gave an example of climbing a mountain, that you see your goal and it feels great to think of getting there, but you won't if you don't start climbing. Sometimes the climb really sucks and you start to doubt yourself, but then you'll get that glimpse at the mountain top a little bit closer and you remember why you're doing it. That makes it easier for a while until it starts to get to be a pain again.
At some point you aren't going to want to do something, but you have to anyway. If you don't, well, that's just being lazy.
My two cents
