I flew 153 combat missions over North Viet Nam in 1976/1968 as a Navy Fighter Pilot in the F-8 Crusader. I specifically remember not experiencing any fear even when the SAMs and AAA were particularly thick and I thought it rather odd, both now and at the time.
I expected to be afraid, but I wasn't. Of course, I was a youngster only 21 and 22 years old without a wife or kids. The really old guys around 30 years old were of two types. A number of them were literally completely fearless, or at least they talked and flew that way. These men were respected by all of us. Most of the other guys were seriously frightened, at least from time to time, but did an equally fine job anyway. They were also well respected. Then there were one or two who really didn't belong there but they didn't turn in their wings because they had a career to protect. So they found a way to avoid the tougher missions by claiming a malfunction or faking a radio failure prior to launch. These pilots were not well respected........... no surprise there.
Personally, I was having a ball. I have a vivid memory of telling myself that I was living life as if I were playing a part in an exciting movie. That sounds strange now, but it really was fun. That sort of combat flying in the most hostile air environment ever seen before or since is a real test of one's flying skills and demonstrating those skills, it seemed to me, was something quite satisfying. Of course it helped being totally convinced that I would never get shot down. I truly believed that, even after watching one SA-2 fly by close enough to read the Russian lettering and noting the failure of the warhead to detonate or when returning to the carrier with a few holes in my airplane. It was dangerous flying indeed and we lost a quarter of the 100 or so Airwing pilots, either killed or captured. But I knew in my heart, they would never get me.
Having said that, I also remember my knees shaking on quite a few occasions after a night carrier landing. This was particularly concerning when some 18 year old Fly One taxi director was guiding you out of the arresting gear and up to the parking spot on the bow with your port side main gear rolling along less than a foot from the edge of the deck, all in pitch darkness. The only thing you could see were his two illuminated taxi wands. Then, since the seat of the Crusader was forward of the nose gear, they would taxi you out over the bow before signaling a sharp right turn to spot you on the bow. Precision steering (using the rudder pedals) when my knees were clacking together added to the challenge. I don't remember being afraid, but it's obvious my knees were scared s**t-less.
Of course, the anxiety associated with night carrier landings in the F-8 is the same with or without combat. In fact, the Aviation Physiology guys put heart monitors on a few guys and took blood samples from the rest of us to determine when we experienced maximum stress. For the F-8 guys catapult shots produced moderate anxiety, combat flying produced the least anxiety, and landings the most, especially night landings. We could have told them that and saved them the trouble.
In retrospect I should have been frightened but I guess I was too young, too stupid, too uninformed, too full of my own B.S., too confident, too highly trained, too good, and simply too afraid of being afraid. It worked out though and if I could recreate any part of my life it would be those year of carrier operations in the Gulf of Tonkin.