The wheel landed on a five.
"Congragulations! You'll get to relive your whole youth!"
At the barker's strange words you find yourself very curious to just what he meant. You had probaly just one some kind of strange toy from the 80s or something.
Then at that moment, the barker hit you over the head with a stick. It didn't hurt but it was annoying.
"Hey! What was that-!"
You stop as you notice your voice was a lot higher pitched than it was a moment ago, and your clothes were starting to feel loose.
"What's-!?
Once more you stop, suprised by your even higher pitched voice, like a child's. Your pants and underwear fall off, and your shirt is now like a tent. Trying to walk, you trip over it, and in the end squirm out of it just trying to stand up.
Whatever was happening stopped, and you looked into a mirror on the stand. A five year old stared back.
"What did you do to me?" Your voice is so high pitched.
"I just gave you your prize. You rolled a 5, you are 5."
"But...."
"Should have read the rules kid, and you might want to find some pants."
At this, you realize you are naked, and standing in the middle of the carnival.