I have some bad news: it doesn't stop in university. In fact, it probably gets worse with the addition of dinner.
Luckily, at my university, the cafeteria is always well-stocked with buns. These have become the weapon of choice, which is good because they aren't themselves messy (although they tend to bounce off things that are) and are soft enough to cause only momentary discomfort.
The worst memory I have is the high-table dinner in Frosh Week of my first year. There we are, all dressed up in graduation-style robes, and after the last alumni finishes their speech, the buns begin to fly. I'm not sure if it made things better or worse when the alumni themselves joined in...
What I want to know: why, when they finally have complete privacy allowing them to have lots of sex and do lots of drugs, do students feel the need to be messy as well?