Sick again

Everyone at my house has been sick in the last three weeks, so I wasn't surprised when I started feeling ill last Saturday. I didn't figure I'd be lucky enough to escape. But how come everyone else got off with a sore throat and cough and I had to end up puking in my friend's toilet? Huh? Could someone please explain the fairness of that? I mean, our trip was meant to be for Stephen's birthday so he could have "adult time" and sit down and play a game and talk and stuff, and I managed to be all ill and lightheaded and go to bed early and ruin it. Nice. Good thing I didn't crash the car or anything too ... wait ...