I find the older I get the more uncomfortable I am at heights. I've worked at various levels doing a shaft realignment and guide replacement on 3,000 foot deep mine shafts and it didn't bother me at all. Of course visibility wasn't much more that 10 feet, so what you can't see can't hurt you, right?? That was thirty-five years ago. Watching that guy make the jump made me pucker, and I don't mean my lips.