I can empathize with that person's fear. I wouldn't say that is my "greatest" fear (being horribly crippled and disfigured by some kind of nasty accident, and living in pain and dependence takes that spot) but it is definitely something that I think about.

At least in my case, it isn't so much that an average life is "bad"; I am obsessive about personal development, and I push myself extremely hard. Ending up "normal" would basically mean my work had been futile, which would be pretty depressing.