One of the BEST experiences in my youth: the Duke of Edinburgh Award programme ( @DofE). Aged 14-18, I achieved bronze, silver & gold levels; did expeditions all over the country; met lifelong mates & mentors; lots of volunteer work in the local community & learned so many skills!
For a couple of years after that I became a @DofE instructor, volunteering at my local youth centre, mentoring young(er) people and passing on all the valuable skills learned from DofE (e.g. teamwork, reading a compass, building tents, first aid, using trangias etc)