Motivation...or lack thereof

Motivation...Such an intriguing thing. I always wondered what motivates us, but after today, I'm more interested in what immobilizes us. You see, this weekend I got to watch 6th grade girls volleyball.  I've never played the game so I don't know much about it.  As I'm scanning the teams, trying to figure everything out, I noticed the varying levels of athleticism.  There were divers, diggers, hitters, servers, the hyperactive ones, and then one in particular that looked like a deer caught in the headlights.  That one stood out because not only was she mine, she was stiff as a board, immobilized by some unknown force that invisibly glued her feet to the court.  Every once in awhile she'd shake her trance and get in a hit, but for the most part she was frozen.  I was so confused. Is this the same child that bounds around the house bossing her brother around? Who's always so at ease? Where is that girl? Who is this imposter? 
I asked her about it afterward. Her reasoning was if she didn't do anything, she couldn't mess up. Is that common logic? By not doing, we essentially take away any propensity toward making a mistake?  While that logic may be true, what kind of life are you living?  I can't imagine not riding a bike or leaving my home or trying something new because of fear. Instead of letting fear be the deterrent, let it be the motivator. Work through the apprehension; let it fuel your determination to do what you set out to do.  Timid deer don't make much progress in life, except further down the same side of the road.