I love it most of the time, but there are times when I really don't feel like it, but do it anyway, because I know I'll feel better afterwards.
There are the few occasions where I get lazy and miss a few days (a few days more than my off days) and I start to get pissed at myself, then go right back into it.
Luckily that's not very often.
It's a hell of a lot better than I used to be. I used to get psyched for about 2 months, then fizzle out for a month or 2, get pissed, and start the cycle over again.
I think I've gotten to the point where, if I stop for a long period of time, I would lose a lot of what I worked hard for, and that scares the shit out of me enough to keep me going.