Not 100% sure of the exact date, but it was whilst I was basic training for the Army. We climbed Tryfan and then onto and over Bristly Ridge to the Glyders. I always remember, climbing bristly, was the first time I ever had that feeling of "Oh my God, I'm falling" my pack was pulling me backwards on the steep scramble up. Tryfan and the Glyders were some of the trickiest scrambles I have done to date. 1 day, I'll return, and do them again.