I live and fly in what are high density altitude conditions in the summer. I'm constantly aware of high DA and aircraft performance. I have also nearly killed myself once, and scared the crap out of myself a few times.
ADM and DA rarely seem clear cut. Sure, if your on a dirt strip at 8000 feet, you probably have no trouble making the right decision. But what about 3900 feet on a 95 degree day? Some might not even check the performance charts (of course this excludes all those on this board...). And then you forget about that 25lb bag of junk you left in the back. And after your run up, you push that mixture knob in all the way, like you normally do. And then, something seems wrong because that tiny hill that seemed in the distance when you started the takeoff roll is now growing in the windscreen...
This summer on a runway not far from home, I somehow managed to forget this fact until partway down a runway I should not be trying to take off from.
WTF? How did I make this mental error?
I remember some old saying about it taking seven years to make the same mistake, or something similar. I found a similar trend in my engineering career.
It's like you learn something, but then a bunch of time goes by, and you catch yourself making the same mistake you thought you had already learned.
So far, my occasionally repeated mistakes haven't killed me but when I read stories I can't help wonder if on this day, that could have been me.