I was riding a steep chairlift a few weeks ago. The guy with me asked if we could pull the safety bar down, almost apologetically. We started talking and I asked him how old he was. 42.
I had zero fear of heights when I was young. About the age of 40, I started getting intense vertigo. I couldn't walk along a cliff (the cliffs of moher were intense) and it was scary to climb a ladder. And it gradually faded away, mostly gone now. I've had other guys say the same thing, fear of heights kicking in around the age of 40.
The guy and I agreed that it didn't affect our skiing.
This doesn't bother me now.