May of 2007, in Shenandoah. I was doing field research for grad school and was collecting samples all along the northeast, from Shenandoah to Acadia NP, so I was pretty close to the AT for the first half until around Harriman. I don't really remember where in Shenandoah it was, but I had some free time and parked near the trail, walked down it for a mile or two, then turned around and walked back. It just amazed me how far it stretched. I'm sure I stepped on the trail at a few other places along that trip, but I never really came back to it purposefully until moving to Carlisle in 2012 and getting into a hiking meetup a couple years ago.