Cut my teeth night flying over the sea.
Probably 60 - 70% of all my naval flying was totally negative external visual references. One quickly learns to worship the Rad Alt, relies heavily on the co-pilot for another. One became fatigued quite quickly - burning holes in the instruments. Watching every twitch and rate change of all the needles. 40 feet above certain death - and far away from "mother".
Then the time came to 'recover' and land on this light shadow moving against a darker shadow, watching and waiting for the 'lull' picking your moment when you literally throw 9 tonnes of thrashing metal at a space no bigger than a squash court.
Deck lights come on, smiling people emerging from the darkness, aircrew nervously laughing - just another normal night op......................
The innocence of youth.
In answer to the OP: I guess it's down to training and discipline. Oh - and how much you value your life, I suppose!