Oh! It's nice to see the monster group come prowling into my day unexpectedly. I clicked hoping to read something enlightening by a group theorist, but five hours in and no comments yet.<p>The sporadic simple groups are these things I've heard about but feel mostly like mythical creatures to me. One day I'd love to have a nice, geometric intuition for each, and it seems like this is slowly becoming possible for the monster group!<p>Anyway, I'd love to hear any stories people have working with the sporadic groups.