It is the feeling you get when after something has happened you think of all the things you could have said.

It originates from the french phrase 'L'esprit d'escalier' litterally translated as 'Wit on the stairs' meaning the feeling you get when you fall down the stairs you think of all the witty things you could have said but didn't.

It’s an acronym standing for Can’t Remember A Fucking Thing. It’s usually used to describe embarrassment at being unable to remember someone (CRAFT moment); going onstage as the lead in the latest theatrical performance and your mind goes completely blank (CRAFT situation); the next morning after a night when you got pissed as a fart and woke up in bed cuddling a traffic cone and a string of fairy lights wound round your prick.