Rotten TomatoesAt a talent show in 1986, young Justin Schumacher suffers a head injury and slips into a coma. Twenty years later, Justin (Jamie Kennedy) awakes with the mindset and experience of a 12-year-old. He decides to reunite the members of his former dance team and revive their short-lived careers.
https://www.rottentomatoes.com/m/kickin_it_old_school
I watched this in high school with a bunch of other 17 year old boys and it was without a doubt the funniest movie I had ever seen, probably would have been about 1/5th as funny by myself.