Graveleye's post in the Camps Gulf Topic made me think of the time a bunch of us went into Holloch for mainly a reconnoitering/supply trip prior to our winter of 1977 expedition.
Accompanying Bill Combs, Chuck Pease, Marcel Brandlii (Swiss caver) and I was his friend, an Army Lieutenant (we were all in the service back then). This guy was quite large, very physically fit and not overweight. He had been caving several years before he arrived in Germany.
We did a round trip to Bivouac II, the Red Carrot and a couple of other well know features in the cave. Anyway, this guy was often remarking how big the passage was and that sections just seemed to keep going and going. Bivouac II is about 2 miles from the entrance and you were waling uphill or climbing fixed ladders most of the way.
On the way back this guy fell apart and we had to 'rescue' him from the cave using an improvised litter. The sheer size and length of the cave passages had simply boggled his mind.
As far as I know he never caved again.
I also thought of this event while reading Bill Steele's book, Huautla. It is an absolutely superb book of expedition caving in one of the world's biggest & deepest cave systems. Bill is an excellent writer.