When things are going well... it's easy.
The Dodgers are winning = I'm such a huge fan!
The songs are just flowing = I want to play guitar all the time!
I feel good after every workout = I'm gonna run everyday!
But then things don't go so well, and you'd rather be doing anything else, like lying in bed watching TV, or lounging on the couch on your iPhone, or sitting at a computer looking at really expensive triathlon bikes.
Those are the times when it's most important to focus and stay motivated and keep plugging away. Because the pendulum will swing, the tide will turn, the momentum will shift... and things will become easy again.
On a sidenote... the muppet on top of Rachel's desk is really scary in the dark...