hair up your ass
That thing you think of when you’re barely awake and it sounds like a good idea until you realize it’s the dumbest thing ever.
I had a hair up my ass idea to live in a cereal box and eat out of a soup can.
My hair up my ass idea was to text my friend and say I’m a robot.
I had a hair up my ass idea to run a race in pajamas and wear my shoes on my hands.