lost it in my drink
Could be used anytime you forget what you were saying or doing, while you’re drinking.
“Hey! What was the score of the game?”
“I don’t know. I must have lost it in my drink”
“I can’t find grocery list! I must have lost it in my drink”
“I don’t know. I must have lost it in my drink”
“I can’t find grocery list! I must have lost it in my drink”