sleep buff 

When you get better at something because you slept on it, probably because your brain worked through some issues you were having but you were too tired/stressed to realize it at the time.

"I couldn't beat a medium difficulty Rock Band track, so I got a sleep buff and handled it just fine on the first try the next day."

sleep buff by randomacct128497124981 December 27, 2023

buffer sleep 

When you're asleep, and people keep waking you up.

Person 1: "Did you get any sleep last night?"
Person 2: "No, I was having buffer sleep."
Person 2: "My siblings kept waking me up."
Person 1: "They must be annoying."

buffer sleep by ByrdIsThaWyrd June 14, 2016