Context: Me and some friends were playing a version of Dungeon of Doom that was adapted for 5e. There was a Kenku Rouge, Bugbear Bardbarian, and me, a Wood Elf Monk with boots of speed.
DM: You open the door, there’s a stairwell. All of the steps seem magic.
Me: I take out my short sword and tap each of the steps as I go up.
DM: What’s your speed?
Me: 60, why?
DM: As you step onto the second step, your speed is doubled.
Me: Holy shit, is that permanent?
DM: It might. You loose control of your momentum and fly up the steps, hitting each step, each one doubling your speed. There’s an iron door at the end of the steps.
Me: how many steps are there?
DM: counting the ones you’ve already hit, 70.
Party: Well shit.
Me: I click my heels together and activate my boots of speed. If I’m gonna die I’m going out with a bang.
Party: Well fuck.
DM: Ok, so, at the bottom, you are traveling at 168843120476043.6*the speed of light.
Party: HOLY FUCK!
DM: Congratulations, Monk, you just caused the big bang. Everyone dies. Universe resets. We’re restarting next week.