The Big Bang Theory: 10 Things You Completely Missed From Season One
7. Howard's Parents Were Still Together
Howard first mentioned how his father left him when he was only 11 in Season 3. Unable to process being abandoned, Howard assumed his dad had ventured to ALF's homeworld of Melmac and would return one day. Even though he doesn't talk about his father much, the fact that he deserted his family has obviously shaped many of Howard's deepest insecurities. In Season 6, an entire episode was dedicated to Howard receiving a letter from his father and deciding whether or not he should read it.
However, this massive backstory is contradicted with a single throwaway line in the eight episode, The Grasshopper Experiment. In the episode in question, Raj whines to Howard about how his parents keep pushing him into an arranged marriage. Raj hates the idea, saying he would never speak to his wife once the two were wed. Howard points out that, "It worked for my parents," implying his mother and father are still together.
Since Howard doesn't mention his dad leaving until two seasons later, most viewers had completely forgotten this paradoxical line by this point.