3rd year in high school we went for a weeks retreat to a massive house in the middle of nowhere that the school owned and the second morning we (about 12 of us) jumped out of the window and walked for hours until we found a town and convinced some man to go into the shop to buy us cider, we all ended up drunk and where having a great old time until the teachers found us.
They grounded us for the rest of the week
We weren't even allowed to leave the house to do the planned activities along with everyone else but it was still a great week just because of the laughs we had.