John Travolta began taking Scientology courses before his audition for the TV show Welcome Back, Kotter, and fellow students pointed in the direction of ABC Studios to telepathically communicate: ‘We want John Travolta for the part.’ (He got the part.)
Thankfully, Horshack got the part the old-fashioned way. He raised his hand and said, oooooohhhhh! oooooohhhhh! oooooohhhhh!