this phrase was derived from tv serial game of thrones , addressed to john snow by two female characters of the serial in a state in which john acted reasonably.
A person who misses a bang bang opportunity acting like a wise ass.
A smart ass treating like a guy from 70's
having refused my girlfriend's tempting request for spending the night in bed with her, she just said you know nothing john snow.
Buy a
you know nothing john snow
mug!
1-Christ's or Santa Claus's food .
2-any tasty food
Do you have anything here to eat?” They gave him a piece of broiled fish, and he took that holy chow and ate it in their presence.”