My immune system isn't as strong as others, I get flu more often than most people. It is quite unfortunate because now, though I get it so often I just figure it out to be a normality. I got the flu two days after my sister's wedding, I was being sick in the toilet for at least an hour whilst watching Vine videos. I seem to be sick when I get flu, because of the upset stomach, I seem to puke things up, not something that many people get.
I'm just unlucky, I still try to not allow it to affect my attendance at school where possible though! So for the people having days on end off because they've got a runny nose, can forget off.
Also I'm asthmatic which sucks when I get flu, can barely walk otherwise I get short of being able to breathe. I try not to whine about it though, this is the odd occasion.