References to Charlie's age here do not match. He says he's 39, and his mother, Evelyn, says he's 40. So far, so good. Then, Dorothy, his current girlfriend's mother and a friend of Evelyn's when Charlie was born, says that he was born in the '70s. Assuming the show is set in "present day" (first air date 11 December 2006), that would mean Charlie was born in the mid-1960s.