not know what hit you

US /nɑt noʊ wʌt hɪt ju/
UK /nɑt noʊ wʌt hɪt ju/
"not know what hit you" picture
1.

no saber qué te golpeó, quedarse de piedra

to be completely surprised or overwhelmed by something, often something negative or sudden

:
When the market crashed, many investors didn't know what hit them.
Cuando el mercado se desplomó, muchos inversores no supieron qué les golpeó.
The boxer landed a punch so fast, his opponent didn't know what hit him.
El boxeador lanzó un puñetazo tan rápido que su oponente no supo qué le golpeó.