What got me was the flashbacks after playing the first time. Lying on me bed, utterly shattered, started daydreaming and I'm back in the woods, looking at trees and ferns and things and then all of a sudden, see a mask and then zap! I'm wide awake and ready to plant a shot into it! Made me glad I just do this with paint!
Also remember the four days of sore muscles that came afterwards - especially the thighs from all that crouching. Every time I walked down a flight of steps - ouch-ouch-ouch-ouch-ouch