I don't remember them all in order. They just randomly come to mind and I will put them here when I fill like it. I wish to have them all here but this is the first time that I actually do it. I've been wanting to do this for a long time. I hope this will continue as I hoped.
So for the first mischief. I remember that I used to go to the rooftop of my hostel, just to lie down and look at the sky. We don't have Netflix back then, so it's just chilling and stargazing.
It wasn't that hard to get to the rooftop. Each floor has their own laundry hanging area, and the third/top floor had an square opening with a metal ladder. There was no hatch. You can just jump a bit and grab the ladder and climb up to the rooftop. It was as easy as that.
There were not much stars to see due to light pollution from the lampposts below. It didn't help either when the moon is full, but at least the moon was beautiful and it was way easier to navigate the rooftop with the moonlight.
Of course this was not allowed for safety reasons and that was the main reason for stargazing: we had to lie down to avoid being seen. And, yes, this mischief #1 was the least of them all.