Casey Affleck regrets being disrespectful about awards season. The 48-year-old actor received a number of award nominations, including Oscars, the Golden Globes, and Screen Actors Guild, for his role in 2007’s ‘The Assassination of Jesse James by the Coward Robert Ford’ and he admitted he wishes he had taken it more seriously. Speaking on The Hollywood Reporter‘s ‘It Happened in Hollywood’ podcast, he said: “I was chewing gum at some award show and people said, ‘Who does this little punk think he is? Like he’s on camera chewing gum at the SAG Awards.’ And that I wasn’t taking it seriously enou…