I Gave My Grandkids a Fake Pet Dragon

Last week, my grandkids came over for a visit and I was feeling rather mischievous. So I decided to play this little prank on them: I made up a story about finding an egg that hatched into a baby dragon in the backyard. They were so excited! We built a small den out of blankets and cardboard boxes for their 'pet,' even got creative with a couple of glow sticks as its eyes. Of course, they asked me questions like what it eats and if dragons can breathe fire, which I had to make up on the spot because who knows? My imagination ran wild. Now they come over every day asking for updates about dragon sightings in the neighborhood. Am I nuts for loving this prank too much? Is it normal for grandparents to sometimes want to be a kid again? What do you think?