Life How lovable ‘Big Bang Theory’ pals matured (well, not always) over the show’s 12 seasons May 8, 2019May 16, 2019 Bill Keveney, USA TODAY Comments Off on How lovable ‘Big Bang Theory’ pals matured (well, not always) over the show’s 12 seasons 'The Big Bang Theory' co-creator Chuck Lorre, cast members credit character evolution as a major reason the CBS sitcom lasted a record 279 episodes.