Springboard diving and skateboarding. The thing I loved about the two of them was no one was ever looking for a winner, we only cared about other people doing their best and landing new tricks or new dives that they had never achieved before. You could meet the best diver or skate that didn't know you, but realized you attained something special at that time and they shared the moment with you, even if they had done it years before, a feeling of brother/sisterhood.
