Either of mine would probably involve tripping on a particularly good batch of shrooms ...
Rode in the back of a truck with a friend, the driver was his friend who I'd never met - who turned out to be
absolutely fucking crazy. He was driving 50mph, swerving / drifting all over, on road and offroad as we're unsecured in the back. And after we smoked out in the words he just got worse .. that was freaky shit, I really expected to be flying out of the truck any second. Luckily that kid got busted for a bunch of other random crap.
The same batch, another time; I ended up having to give my roomie and his gf a ride around town to pick up some food, then to the library. I only had to drive about a block off campus, but it was dark and I thought I was lost. I couldn't even speak coherently. But I didnt' want to tell them I was shrooming and couldn't drive
The only time I had to directly talk to a cop was when my friend and I rolled up on a sobriety checkpoint as I was hitting a bong. I unsuccessfully hid the bong, but I was truthful when I told the cop I had nothing illegal on me - a search confirmed this. Good thing they didn't bother to search the car much :D My friend was driving, it was his car, so I got to walk home about 10km, stoned and scared as hell.
Another time (first time on K) some cops busted the 2nd party of the night, 500km away from my home, I thought I was f*d. Luckily I'd just turned 18, and there were so many people at the party that the few cops didn't have the time or patience to check everyone's IDs ... trying to walk in a straight line, following some people you just met to their car way down the street while police stood and watched us wasn't exactly 'comfortable' though.
There were a couple hundred people at that house, and 90% of them were on e/k/both.