Classic Mary Jane Jokes. Mary Jane was walking on the beach one day and saw a shark swimming around a man. The man was screaming, "Help me! Help me!" And Mary Jane laughed and laughed, because she knew the shark was never going to help that man! Mary Jane was on the hilly streets of San Francisco when she saw a baby carriage rolling fast towards a busy intersection with the mother screaming, chasing the carriage. And Mary Jane laughed and laughed, because she knew there was a stop sign at the bottom of that