There's something about following a routine. For instance, it's more efficient to have a study routine than to only study when one feels like it.
When I was still learning the keyboard, I once saw someone play really fast arpeggio-runs on TV and I knew what he was doing, but wasn't able to do it myself. So I started to practice (for about 5 minutes) everyday with the hope of being able to do it. 3 weeks later I was able to play fast arpeggio-runs.
Now this happened completely by fluke because I din't have a teacher to tell me how to practice. But I've always known that all I need to do is practice. Even to this day, if I find a section difficult to play, I know I'll get it within 3 weeks. If I don't I shelf it for later, because it's probably above my skill level.
Last December, I happened to read this self-help book called Attitude is Everything by Jeff Keller. My favourite chapter in that book is chapter 4 on commitment. It starts with this quote from Graham Bell:
What this power is I cannot say; all I know is that it exists and it becomes available only when a man is in that state of mind in which he knows exactly what he wants and is fully determined not to quit until he finds it.
— Alexander Graham Bell
The word commitment tends to have a negative connotation associated with it, unfortunately. I think it's a beautiful thing to say "this is important to me and I'm going to make time for it, and put some effort into it". Why spend my time distracting myself away when it could be employed on something that is important to me?