"I'm an excellent driver."
Remember Dustin Hoffman repeatedly saying that in "Rain Man"? Which mundane activities are you convinced you do well? Or excellently? Try limiting your answers to activities that would be difficult for others to refute.
For example: Are you a good (or excellent) parent? Are you good (or excellent) at sex? Are you a good (or excellent) conversationalist? How many people do you know who would say they were average (or worse) at any of those three things? Consider that number for a moment. So, what does it mean to be good (or excellent) at parenting, sex, conversation, driving?