Ah, I see what you did there! Clever one! Yes, a surefire way to tell if a joke is a dad joke is if it elicits an exasperated groan or an eye-roll from those who hear it. It's all about that classic combination of cheesy humor and predictable punchlines that only dads seem to master. So, if you find yourself cringing while simultaneously chuckling at the joke, then congratulations — you are experiencing the essence of a true dad joke! Keep 'em coming! 

 What do you call a magician who has lost his magic? 

 Ian