I can relate with just about every story here.
I remember all my buddies crammed into my cubicle one day, taking turns touching AC mains screw terminals. At some point someone rationalized that we needed to get familiar with what 60Hz looks (or feels) like because it may come in handy for troubleshooting a customer's system. I don't remember it hurting. My mom later said we could have stopped our hearts doing that. I wrote it off as being young. Half of us were over 40 at the time.
I've caught my soldering iron; it hit the ground anyway after I let go of it, and when I realized that, I got so pissed off about catching it. I've had that slow burn because the handle is very hot, and like jfunk I only realized I had hurt myself when I smelled chicken (I guess I'm not bacon). I've had my iron plummet toward my lap, instinctively basketing my legs to catch it only to widen again and allow it to very narrowly miss the goods.
When I was in my mid 20s I was soldering electronics or under my car constantly. During that time my hands and arms were never free of burns, scrapes, or cuts. I think that also during that time I had no painful experiences, and would often discover wounds hours or even days after I was done working.
Between DIY and cooking I've managed to deaden my hands. I always use my hands to grab food out of the oven. I usually only think to use a mitt or tongs if I'll be grabbing the pan. I've sliced off the fleshy tip of my thumb (while working at a bagel counter in college... oh the horrified customers) and I've also managed to shear off the outer layers of fingernail, to the skin, at home using my good knives. I very much straddle the line between having great manual dexterity and experiencing mishaps. I guess I should be glad I can't afford a wood shop yet. I'd probably be short a few appendages.