Formative influences with hiking, camping, and the outdoors from my dad and grandfather as a youngster. When I made it to college I fell in with the right crowd that turned me on to some rock climbing and mountaineering. We also did some spelunking but that did not stick with me...more interested in the light of day.
Interestingly my early experience with scouting was a disaster as well. I was in a cub scout troop (during the 1960's Vietnam error (pun intended)) that was all about visiting police academies and military bases and turning us into good little soldiers rather than exploring the outdoors. Even as a grade schooler I only lasted a few years with that stuff before I said "enough". My dad had been highly involved with scouts in his youth but I think he understood.