It reminded me of the time I was carefully treading across a fallen tree which made a path over a ditch and the guide told me the mud underneath wasn't a soft as it looked. It didn't look at all soft.
I didn't really need the warning about the cactus.
I'd discovered, as a teen, in an area that had few cacti, that just one can be unpleasant. I didn't think I was sitting near it, but I learned that a safe distance from a cactus is a little farther away than I expected.