knock yourself out = please begin doing it
Ex. If you want to make hotel and airline and car reservations and take care of everything, well, then, knock yourself out.
A friend is staying with me for the moment and one of his favourite idioms is “Knock yourself out!”
I know that I should not take this literally but that’s what my brain does!
Last week, I fell on the gravel path during my regular run… I knocked myself out!
This week, I fell from my push bike… I knocked myself out!
Some words are so powerful aren’t they!?
So… I have asked him to avoid saying “Knock yourself out!” I rather stay alive and in good health 🙂