Youtube: Ann-Margret, Oliver Reed and Robert Powell in the key scene from Ken Russel's film of The Who's rock opera "Tommy".

Tommy's biological father, long thought dead, and unaware his wife has happily re-married, suddenly reappears and is accidentally murdered in the presence of Tommy, who is then so well "convinced" that he didn't see or hear a thing and must not say a word that he actually goes blind, deaf and dumb; effectively going autistic.