I think before you even start to learn to climb you'd better grow some balls, or at least check them. A good climber never doubts his abilities. Think of it this way, you can do it, you just have to learn how. Working out of a bucket musta made you soft. Didn't you climb before you started in a bucket?
That's what's wrong with the young folks now a days. They go to a "School" think they learn everything, then get out and want to go to work right at the top. My advice and training methods are:
1. Start on the ground. Learn to be the best ground man possible. Watch the climber and bucket man as you work for them. Learn what they do, ask why and how.
2. Start climbing when the foreman thinks you are ready. Learn to be the best climber possible. I perfer learning from a old timer, but the schools do add some value.
3. After you got some years under your belt as a climber, then learn to use a bucket. Then you will have mastered all the basic skills of tree climbing.