When you have to get up in the middle of the night to pee after drinking copious amounts of water the evening before. Typically leads to a lack of sleep and the constant need to go to the bathroom every 5-10 minutes.
You're usually so damn comfy you tend to lay there in your bed and contemplate whether or not you should get up and go to the bathroom.
Worst comes to worse, you fall back asleep and dream of toilets and whizzing only to wake up with a swollen bladder with enough urine to water your neighbor's houseplants.
"Man, I shouldn't have drank so much last night, I got some serious case of the night piss."