not know what hit you

not know what hit (one)

To be extremely shocked, surprised, or confused by something. When my father passed away, I just didn't know what hit me. With this new strategy, our opponents won't know what hit them.See also: hit, know, not, what

not know what hit you

be hit, killed, or attacked by someone or something without warning.See also: hit, know, not, what

not know what ˈhit you

(informal) be so surprised by something that you do not know how to react: You should have seen his reaction! He didn’t know what had hit him! OPPOSITE: see something comingSee also: hit, know, not, what