5 Things You Didn't Know About 'The Big Bang Theory'

The cast and crew of "Big Bang Theory" opened up immensely about the series at PaleyFest.

The annual series follows panel discussions of current TV series for one week in Los Angeles.

The stars and producers of CBS' hit comedy took the opportunity to reveal secrets from the set during its panel Wednesday evening.

The Hollywood Reporter compiled a list of 15 items the cast and crew shared.

From the origins of Sheldon's get well "Soft Kitty" song to catchphrase "Bazinga!", see the top five things the stars of the show revealed.