Unless you enjoy being ill, I strongly dissuade you from two things.

1. Going to university.  Freshers’ Flu is not a myth - I repeat, not a myth. It is a real and terrifying phenomena brought about by the mixture of several hundred people from different corners of the country and all their germs. I developed Freshers’ Flu around the first week of term and it has to date lasted over 15 months. That’s right, it never goes away.
2. Travelling to/from a foreign country. Especially just after having begun to feel better following a cold or flu. If you do this, which I have done this Christmas, it is an almost 100% certainty that you will catch something straight away and then feel awful for the rest of your trip.