Don't have grandkids yet but my niece pulled this one on my Mother. Mandy was about 4, sitting on her grandmother's lap, playing with Grandma's watch. Finally she said "Your watch is so pretty. Can I have it when you get old?" Grandma said, "Sure, I guess you can have it." They rocked for a little while longer and then Mandy looked up innocently and said "You're really old now aren't you, Grandma?"