knock (someone) for six

British & Australian, informal

to surprise and upset someone a lot.

It really knocked me for six when my ex-boyfriend announced he was getting married.

• have a lot to answer for
• have a memory like an elephant
• have a memory like a sieve
• have a mind like a sieve
• have a mind like a steel trap
• have a mind of its own
• have a minute to call own
• have a minute to call your own
• have a monopoly on
• have a monopoly on something
• have an ace up sleeve
• have an ace up your sleeve
• have an axe to grind
• have an ax to grind
• have an ear for
• have an ear for something
• have an eye for
• have an eye for something
• have an eye for the main chance
• have an eye on the main chance
• have an open mind
• have a nose
• have a nose for
• have a nose for something
• have a nose round