BrainFart

A BrainFart is where you are talking and suddenly forget what you were talking about, and realise you started rambling about something else.

A: so i really want to eat pancakes
B: ok cool.
*few hours later*
B: what did you want again?
A: pancake? im pretty sure i said that a while ago because i was hungry so i wanted a... what did i want?..
B: did you just have a BrainFart?