The most common reason I fail is lack of focus.
If I don't know what I'm aiming for, then it makes going in any direction one full of doubt. Do I do this? What if it doesn't work?
No focus causes me to procrastinate.
No focus causes me to stress.
No focus causes me to blow up the importance of insignificant things.
Anytime I've ever made it clear to myself what I want, that focus carries me through to success.
Reaching that pure focus is one of my most favorite feelings -- but elusive.
I'm going to find it.