I've had it loads of times (3 kids at different schools, husband teaching at a 4th institution, my job involves lots of travel, and to top it all it's endemic at our local hospital, a hospital at which about 50% of the parents at two of the schools work). I've had it badly 3 times. The first time I didn't know what had hit me, I was scared, but I had no kids, it was sweeping through DHs place of work, I just took to my bed in my own home and rode it out.Fine.
The next time - I was in Tallinn attending a conference. Tallinn. Which isn't a great place to be at the best of times - and this wasn't the best of times, it was in the middle of the coldest winter they had had for years, people were being found frozen to death in the streets all over the baltic and russia and it was allegedly about -30 in the evenings/nights. The allegedly posh hotel in which I was staying was bad anyway.
It was a whole lot worse after my night from D&V hell which destroyed the plumbing (among other things).
I thought I was going to die. I thought I'd never get home.
I didn't due, I did get home but it was appalling. I pretended to be upduffed when flying home to explain the copious V (the D had stopped by then). But it was awful.
The next time, we were on holiday in Cornwall and all 3 of the kids had it too. Vom-geddon. Squitpocalypse. The drive home was......interesting.
Since then, the kids have had it but not me. I'm love to think I'm immune but.....I know I'm not.