For example, if I made a commitment to a friend of mine to go out jogging, I'd do it. So... clearly my word matters. However, when I tell myself I have to get up early and go jogging, it doesn't always get done. So looking at it logically, I definitely honor my word... at least to others! I think we all tend to let our own commitments to ourselves slide at times. "We always can do it tomorrow." Yes, that's true, however, that means the things we wanted to do tomorrow may never get done because of the things we have to do today. And so on and so on.
I think that as much as we can recognize that our commitments matter even when they're made to ourselves, the sooner we can move our lives forward in the ways that we choose. And by moving our lives forward, we can ultimately accomplish what we want to accomplish.