Seriously, you sound like a two-years-old boy.
The AGE UP / AGE DOWN meme
(1) Comment your character aged up or down. Play the character any age that is not their current age. Make them a kid, a teenager, an adult, elderly, whatever.
(2) Other characters reply with reactions.
(3) Whether or not they retain their memory or their original age's mentality is up to you!
(4) Same on age/mentality commenting to others. They could react to a kid!version of a friend in their normal adult age, or be a kid themselves!
(5) This is pretty loose, ANYTHING GOES. GO CRAZY, GET CREATIVE.