The Power of Belief
No, this is not about religion.
This is about systems. One pattern that I've noticed when helping others with their systems is that believing (as in truly without-a-doubt believing) is key to success. When you doubt a system, you end of questioning it's worth, and this makes it so much harder to stick to.
For example, exercise. A common problem for people I exercise with is feature creep. We start off with a simple and effective routine, but then think: "We're missing X, let's do it", "I think I could do Y more", "It doesn't feel like we're doing enough", etc. There's always more to do, though. What started out as a simple effective routine might end up much more complicated, ineffective, and time consuming than intended. The solution is belief in the system.
A more recent example is that I've been trying the Pomodoro Technique. I've tried it before, and I was underwhelmed1. Recently though, I've been convinced that it made a lot of sense, and sure enough, have been extremely successful with it (so far).
I'm probably the most skeptical person I know, but it would be foolish not to acknowledge the power of blind faith.
Footnotes:
Remembering that whelm is a word got a sensible chuckle out of me. It's the little things in life.