The purpose of your opening is to loosen up the audience and invite them to listen. The harder you are to duplicate, the more in demand you will be. Personal stories are always best, because they give the audience a chance to get to know you. Vulnerability is your greatest strength. Life is filled with funny examples if you look through the eyes of humor.
Life is just one long anecdote waiting to be told.
Tell the story to friends. Make a note where they laugh. Eliminate unnecessary words and shorten. Put the biggest laugh at the end. A really good story explodes into the punchline, which is nothing more than the unexpected truth that twists reality slightly.