(the) next thing (one) knows

(redirected from the next thing they know)
Like this video? Subscribe to our free daily email and get a new idiom video every day!

(the) next thing (one) knows

All of a sudden; out of nowhere; without warning. I was standing in line, minding my own business, when the next thing I know, a gunman runs into the bank and starts screaming at us to get on the ground! Tammy had only been on a few dates with Mark, but this one had been going smoothly. Next thing she knew, he got on one knee and proposed to her.
See also: know, next, thing