It turns out that Bill Prady's primary inspiration for Sheldon Cooper was not a physicist but actually a former colleague of his (via The TV Addict). "Before I was a writer I was a computer programmer and was working with guys who were amazingly bright and had a little trouble fitting into the world" he explained during Paley Fest '09. "I would tell ['Big Bang Theory co-creator] Chuck [Lorre] about a guy I knew who was a human calculator. If you programmed in Z80 assembly you had to convert from decimal to hexadecimal and you could either grab the calculator or you could shout it to this guy and he would be faster." 

As brilliant as he was, when it came to human interaction, the programmer was lost. Sounds a lot like Sheldon Cooper's difficulties with social cues, right? "He couldn't calculate a tip at a restaurant because the formula for a tip is 15-20% depending upon the quality of the service and he couldn't put a numeric value on the service. It was human," Prady recalled of the computer programmer who inspired Sheldon.

"Big Bang Theory" viewers all over the world fell in love with Jim Parsons' interpretation of Sheldon Cooper, and Parsons worked hard to make sure that they did. The actor described his preparation for the role to "Fresh Air" host David Bianculli (via NPR). "I really just [ran] rampant around my apartment saying these words, this dialogue over and over," he said of his rehearsal strategy. "I'd go outside and say it. I'd sit down and say it. I'd stand up and run while staying it. Because I thought 'I need to be able to trust myself to have these words come out.'"