I got mono from common cup communion at church! I was 15 - it was summertime - and I was sick for over a month! My mom even had the priest come around - I thought he was there for last rights!!! That's how bad I felt!
Is it true you can't get mono again after having it once?
Yep, that's how you feel with mono: like you're going to die. I had a case when I was 14, a case which my doctor at the time said was the worst case he'd ever seen. Nice, huh?
Anyway, no, that's not true. My mother has had it several times. I, thankfully, have only had it the one time.
Oh, and as far as it being very rare to get chicken pox twice (or more) times, it is. Rare, that is. But, I was not misdiagnosed, and I was old enough to remember both of the times clearly. Rare, yes...but not for someone who was born with no working immune system. But, that being said, my area manager claims to have had it three times, and I tend to believe her after having it twice (and bad both times - it wasn't as if once was a light case and so I got it again; I was covered, head to toe, both times). I'm glad it's a rarity, but I think people should be aware that lightening can strike twice (even when "they" tell us it can't).