Hesitation kills your opportunities. What makes it worse, is you lose by doing nothing. You're going to face losses along the way no matter what you do, so at least lose from doing something. Strike out swinging, as they say in baseball.
Speed kills too. And so does a normal pace: We are all going to die anyway. So since you're gonna die in the end, why not make the most of it and go as fast as possible?
Men: Ever have a girl giving you the look when you were out somewhere, and you hesitated to approach her -- and killed your chances with her?
Athletes: Have you seen an opening on the court/field in a game of your sport, but hesitated to "shoot your guns" and missed a chance to make a big play?
Everyone: Have you ever met someone while you're out anywhere, and just know this person could be the exact individual you need to help your business... But you hesitated to connect with him/her?
On those lion shows on TV, the lion never hesitates when it sees potential prey. The lion doesn't always make the kill, but not because it didn't move fast enough. And we all know the lion is the King of The Jungle.
Try acting immediately on things. You won't always succeed, but at least you lose a game you're playing and not watching.