I have two experiences to share. I'll do the positive one first.
Experience: Delivering a baby.
Context: For our second child, my wife and I decided to go with a home birth (an option that was available with the midwife we were using). My son, however, had his own schedule, and on the day of his birth, he came fast...and the midwife was running late. So, I delivered him myself.
In my head: Truth be told, there wasn't a lot of thought involved. It really was a situation of "This is happening - put your hands here and catch!" It was the wee hours of the morning, but as soon as it started, I was wide awake. I knew from the birth of my first child that the umbilical cord could be wrapped around the baby's neck, so I knew to check as the baby came out (it wasn't), but otherwise the baby slid out so quickly that the birth was over as soon as it started. I remember being somewhat numb as I processed it, at the same time as I looked into my son's eyes and realized that I was the first face he had ever seen there was this incredibly warm feeling...which transformed into a "huh...what's this white stuff on my sleeve?" after I handed my son over to my wife and realized that my sleeve was coated with this substance that kind of looked like cottage cheese (apparently, in the womb babies are covered with this stuff for insulation and the like). The experience of the birth itself ended with the midwife arriving and then asking me if I wanted to cut the umbilical cord, to which I replied something along the lines of "I just delivered this baby - YOU can do it."
Experience: Preparing to tackle a potential gunman at a synagogue.
Context: I used to be the vice-president of my local synagogue. During my tenure, alt-right extremists were planning the week of one of our services (at least, I think that was the timing) to do a march through the city demanding racial holy war. The march happened, and we had to decide whether to call in the police for extra security in case the service came under attack. In the end, we decided that the risk of emboldening these extremists by showing fear (and possibly provoking an attack that would not have otherwise come) was greater than the risk of coming under attack, and we decided to proceed with business as usual. On the day of the service, those of us who had been at that meeting all knew that if we got things wrong, it could mean a man with an assault rifle showing up to kill us all. I mentally prepared myself to tackle any gunman if they appeared in the hopes that it could give others the opportunity to escape. Happily, we got it right, and no gunman appeared.
In my head: These things are never what you expect them to be. You'd think you'd be afraid, but there really wasn't any fear involved. Lots of tension, and a not small amount of dread, but fear of dying was not a factor. It really was a "this is a very unpleasant thing I might have to do, and if it happens, let's just get it done." I knew intellectually that if it happened, I probably wouldn't survive, but my mind just didn't care - it was spending its time figuring out the best way to tackle somebody with an assault rifle. On the day, there was a bit of a "coiled spring" type of tension, but that wasn't overwhelming either. I don't even remember being all that relieved when it was over - my recollection of the experience was that it was just "Okay, that didn't need to be done - cool," and moving on to business as usual. I'm not kidding when I say that I have a stronger emotional reaction to remembering it now than I did when it was happening.
