I wouldn't have been such a gentleman and got with more girls.
I wouldn't have sold weed my senior year of high school. Ended up getting suspended for 2 weeks, barred from all school functions, the prom, lost my driving privelages, and had to ride the bus my senior year, had to tuck in my shirt for the rest of the year.
On the bright side they never called the cops and I wasn't going to Harvard anyway so it really had no bearing on my academic future.