Comedian Keith Alberstadt has always been sarcastic. “I was in a wine store,” he tells an audience, “and I couldn’t see the label very well so I asked the woman who was working there, ‘What year is this?’ ” The woman replied, ‘The wine?’ That’s when the sarcasm kicked in. ‘No ma’am. I am a time traveler. I am only here to beg you not to breakup with your boyfriend. Or I’ll never be born.’” The Nashville, Tenn., native has wanted to be a stand-up since hosting a talent show back in high school.gobananascomedy.com.