As far as I understand it, the bulk of the knowledge you gain from going away to college is not from the classroom, but from interacting with new people from different places and various backgrounds. Not that you can’t gain the same knowledge elsewhere or otherwise or whatever, just that college sort of expedites the process and allows you to do it all in a reasonably safe place while getting drunk with some frequency.

Anyway, every student brings something to the exchange: unique perspectives, diverse interests — all that stuff they probably brag about in the student handbook, if there is such a thing.

I brought water balloons. That was my contribution to the Georgetown University campus community from the fall of 1999 to the spring of 2003.

At home on Long Island, my friends and I owned one of those water-balloon slingshots. It was amazing. Also, for some unclear reason, Rockville Centre is like the nightlife capital of Southern Long Island, providing a group of very bored young men with a bevy of unknowing potential targets for water-balloon fire.

Drunk people get so mad when they’re nailed with water balloons. And the hilarious thing about using the slingshot is that the victim never even considers that it might have come from like 100 yards away. A balloon shot from that distance always explodes on impact so it doesn’t really hurt as much as you’d expect. So the natural reaction is only to check your immediate surroundings for the perp. Little do you know he’s comfortably hidden across the parking lot, giggling his ass off.

Actually, thanks to Google Maps, I can show you. The A flag on this one is R.J. Daniels, one of the town’s bars — though it wasn’t called R.J. Daniels then. That red awning behind it is the outdoor-patio area of the bar, which got pretty crowded in the summers and extended out into that tiny patch beyond the awning. Ground Zero, essentially. We set up either on the train trestle (the red arrow on the left) or the parking lot behind the gym, past the elevated train tracks and across the street.

The distance, you will note, provided us ample time to run like hell in the rare instance a posse of angry drunk dudes would figure out that the balloons were launched remotely and come storming out of the bar thirsty for blood.

Once I felt comfortable enough in college to unleash my hobby upon the campus, my friends and I found a great spot. Check it out — the arrow in the map below points to a little-known but easily accessible perch above the main entrance to the campus’ student center. From it, you had a clear but well-covered shot at anyone coming out of the Henle dorms to the north or walking along the main campus paths, seen here in white.

Get a case of beer and a cooler full of water balloons and you’ve got yourself a pretty solid evening out. (Lord, we were losers.) One time we put a balloon between a guy playing guitar and the girl he was trying to impress. Another time, a well-placed shot in the middle of two passing groups prompted a minor scuffle. We knocked a drunk guy over once with a direct hit. That one we felt a little bad about, after we stopped giggling.

For safety reasons we tried to avoid cars. But once, from a different location, we hit a slow-moving black town car heading to a campus function, and then the angry driver when he got out and started yelling. We were told later that the passenger was a certain Senator Biden from Delaware.

Anyway, my sophomore year I caught a case of mono that forced most of my water balloon exploits indoors. Desperate times. I wound up in a pretty serious and ongoing water-balloon battle with my neighbors downstairs which meant I kept filled balloons on hand in our bathroom at most times.

One of those times, some loud and liquored-up students were standing outside in the courtyard, three floors below my bedroom window. Maybe I was jealous that they could still enjoy parties while I was stuck inside sick.

Anyway, I figured nothing all that bad could come of it, so I dropped a balloon quick and ducked inside. This is a close-range shot we’re talking about, much riskier than when we normally targeted strangers. The arrow on the left is the approximate location of my window, and the arrow on the right is about where these people were standing.

I didn’t imagine all that much that could go wrong if I just tossed one out the window into the group. My door was locked, plus most people who go to Georgetown are total weenies.

Only not the particular guy I hit. He was a 270-some pound lineman on the football team, and he and two of his football buddies lumbered upstairs and kicked open my door.

I took the R. Kelly approach: deny everything. The drenched dude asked me if I was throwing water balloons, I said no. He asked me why my window was open, I said it was for fresh air. Then one of his friends made his way into the bathroom and came out asking why I had all those water balloons in the bathroom if I wasn’t throwing water balloons. I said they weren’t mine.

They stared me down for a few anxious seconds, then one turned to the other two:

“OK, this guy’s cool.”

It gets better: Apparently all the commotion prompted someone in my stairwell to call the cops. Before they showed up, the drunk guys went back outside, all fired up and looking for trouble. They found it in the form of one member of the basketball team and two of his high-school friends from D.C.

I don’t know what prompted it, but from my window I watched as one of the D.C. locals stepped to the football guy, punched him in the face and knocked him to the ground. Then he took one step to his right, punched the next guy in the face and knocked him to the ground. Then he took another step and reared back to punch the third guy, only the third guy just sort of ducked out of the way and stumbled to the ground on his own.

When the cops arrived, they found three drunk, drenched, dazed meatheads practically waiting to be arrested.

The postscript is that some of my oldest friends from college were also on the football team, and I told them the whole story a couple days later. Turns out they also didn’t like the meathead in question, and used the story of his ignominious ass-kicking as fodder for harassment for the remainder of their time in college.