The tendency for things to seem funnier in the wee hours of the morning. Even if it wouldn't seem funny had you not been sleep deprived. Usually leads to a laughing fit after saying anything, even if it isn't funny.
Recounts of the events at this time the morning after. are usually segmented and won't seem as funny when given proper consideration of the conversation. Or may result in selective amnesia.
Voltanis: What the fuck did we talk about last night?
Maha: About bears? I don't know. Everything seems funnier after 2 am.