I've often compared going onstage to jumping into a cold swimming pool. If you have to think about it very much, you might not do it at all. As Don Firth has said rather eloquently, be prepared and well rehearsed and then step out confidently and go.

As an aside, my late mother was a registered nurse and a physical therapist in the 1930's and '40's. She specialized in rehabilitation work with polio patients in central California. I remember visiting people in iron lungs and having several schoolmates with braces or in wheelchairs. Most people born since 1950 may not recall the epidemics and the fear and pain that polio caused before Salk and Sabin formulated their vaccines. I salute you, Don, for all you have accomplished in life despite the affects of the illness you endured.