Here's a really nice thought from Neale Donald Walsch, author of Conversations with God, which I have not yet read.
Every decision you make -- every decision -- is not a decision about what to do. It's a decision about who you are. When you see this, when you understand it, everything changes. You begin to see life in a new way, all events, occurrences, and situations turn into opportunities to do what you came here to do.
And, in a similar vein....from Anthony Robbins:
More than anything else, I believe it's our decisions, not the conditions of our lives, that determine our destiny.
So, in a way, your decisions define you. They show how you really view yourself, your self concept, on a subconscious level. Think about it, each decision provides a way to express who you are to the world.
Successful people make decisions quickly and without regret. Other people let fear paralyze them, and spend far too much time second guessing themselves and thinking that they should have done....something else.