There was a thread here about close calls, I think; I didn't read it out of superstition, I guess. But it got me thinking. I have a "gear left behind" story for each of my closest calls, and it's even the same piece of gear.
Once I was skiing on our lower mountain on a powder day and got cliffed out. I was trapped, walking back out was impossible. The cliff looked jumpable. Maybe not by me, but jumpable. So I decided to sort of hip-check it, slide over and half-jump. I'd seen it done. What I didn't realize is that you have to keep your skis up in these situations; one of mine caught in the snow, forcing me to stand up and go over the cliff backwards. I hit the soft snow hard, rag-dolled a couple of times and came to a stop hard, back against a tree trunk. I was scratched up a bit, but OK. I got my shit together, then looked up the cliff, and one of my poles was up there (I at least hadn't strapped on). I came back later with some rope, a probe, kept returning those next few days, but I couldn't reach it. That pole stayed there most of the season, taunting me, reminding me of my folly. I went back the next autumn before the snow came, but it was gone. Nice pole, too. Head carbon.
Another time, our signature offpiste area was closed due to lack of snow, especially near the bottom. It was index 1 or maybe 2 that day. Word was, you couldn't ski through the narrowest part as there was no cover. But a friend and I asked mountain management if we could ski the top part, then skin back up when we reached the unpassable section, and they said sure. We skied it, and it was in fact passable, we made it easily through the narrowest part. It was good enough that we decided to go for another lap. Near the top section, my friend skied ahead. We were in an offpiste section, within view of marked trails, that's skied hundreds, thousands of times a year, by intermediates, kids, ski classes. There was almost no snow. But it slid. A lot. I was on a big block, bigger than me, and it was taking me away; ahead, I could see my friend's head bobbing among huge slabs. I remembered my (limited) training: I threw away my poles, tried to stay upright, and focused on visuals to try and save my friend. It was all over in seconds. I never lost sight of him, though he was buried to the waist. I skied down to him and helped him dig out. One of my poles (new Black Diamond alu/carbons) had made the trip with me, the other was up on a pile of rubble above me. I didn't go back for it, and never saw it again.