Georges St-Pierre on training when you don't want to

Georges St-Pierre makes an interesting point in his book The Way of the Fight, where he talks about how you don't get better on the days that you're 100% motivated, but the days you don't want to come in and train:

“You don’t get better on the days when you feel like going. You get better on the days when you don’t want to go, but you go anyway. If you can overcome the negative energy coming from your tired body or unmotivated mind, you will grow and become better. It won’t be the best workout you have, you won’t accomplish as much as what you usually do when you actually feel good, but that doesn’t matter. Growth is a long term game, and the crappy days are more important.”

That's a very well articulated point, and something that I first read about actually from UFC vet Rick Story. Story made a succinct and point that is exactly the same as GSP in the following quote: