Staying on schedule at first is very difficult. But like any exercise program, prioritizing that commitment is huge. Once you get into the rhythm, you'll find yourself scheduling things around your workout, as opposed to the opposite. Trust me, when you start seeing the results in the mirror, it changes everything. It will become more important to you than sleeping in or going out drinking or partying. The more intermittent your exercise pattern becomes, the easier it will be to just stop altogether.
It's hard at first because you don't visually see any improvement, all you feel is pain, but you have to stick with it. Otherwise it'll end up being a short term venture and failure. A co-worker of mine completely sold me on P90X when he told me his results. He lost 30 pounds over about 120 days. I didn't need that kind of weight loss (8 pounds so far, but more muscle mass), but in order for me to drop 10 pounds in the past, it was dieting and calorie counting. Which sucked. Going to sleep hungry, is not fun. Now I have to make sure I eat enough, so that I'm not starving my muscles. Much more gratifying. Plus, I'm not headed towards thin. I'm headed towards toned.
Anyway, I'm not sure if my little wall of text was inspirational or not, but if you continue on, you won't regret it. If you quit, it's likely that you will.
