Excellent. You must have read my mind - I was about to suggest starting a new topic/poll when you beat me to it. However I doubt I would have been quite as creative with my poll questions as you. Since I was the one who questioned your original comment and opened that can of worms, I guess I at least owe you a reply.
In an absolutist-dogma kind of way, I chose the first answer in the poll because it is the closest fit. Although what I really mean is "when I go caving, I always bring a helmet and wear it almost all the time while underground." On rare occasions I do remove it - e.g in tight, nasty crawls I can't avoid, camping underground during an expedition, when I need to change batteries, scratch my head etc. But I don't actually 'go caving' without a helmet unless you count the lighted tourist trails (I don't).
If I'm ridgewalking I would usually bring a helmet. If I'm just hiking and happen to find a hole in the ground, maybe not. But in those rare cases, I'm not there to push any envelopes. I will usually stay within sight of daylight and/or easy walking passage and/or in voice communication with others. Basically I would be in casual spelunker mode rather than caver mode.
This is just me, and obviously you have a different opinion based on your experience. In the previous topic you mentioned Marion, and said "I think he's a good example of a fellow who can use his own brain to decide what will work for him instead of doing what everyone else does/says." While this is very true, to the best of my knowledge I believe he consistently wears a helmet while caving. It looks that way in the photos, and he was certainly wearing a helmet the last time we were caving together.
I realize cavers can think for themselves and make their own decisions, but helmets are kind-of a fundamental piece of caver equipment the world over. I know you own one, but choosing not to bring it on some caving trips just strikes me as an odd decision for a caver.