you have no idea...

you have no idea

You cannot imagine or understand. I'm sorry I'm late for dinner again. You've no idea how much stuff I have to get through at work right now. You have no idea what it's like raising two kids on your own while still holding down a full-time job, so stop criticizing me about my parenting!
See also: have, idea, no
Farlex Dictionary of Idioms.

you have no iˈdea...

(spoken) used to show that something is hard for somebody else to imagine: You’ve no idea how much traffic there was tonight.
See also: have, no
Farlex Partner Idioms Dictionary
See also:
  • be pressed for time
  • be in it for
  • a run on (something)
  • away from it all
  • be pushed for time
  • a rush on (something)
  • be out of (one's) head
  • be at a disadvantage
  • at a disadvantage
  • address comments or remarks to