have not heard the half of it

have not heard the half of it

To know only a small part of how bad something is, but without understanding the complete situation; to underestimate or be uninformed about how bad a situation really is. Our bosses think that this is a major setback, but they haven't heard the half of it. We're months, not weeks, behind schedule! A: "I heard you and Terry were going through a tough time." B: "Oh, you haven't heard the half of it."
See also: half, have, hear, not, of
Farlex Dictionary of Idioms.
See also:
  • not know the half of it
  • as bad as all that
  • have a bad opinion of (someone or something)
  • have a good, bad, high, low, etc. opinion of somebody/something
  • be downhill all the way
  • downhill all the way
  • it's the story of my life
  • story of my life, the
  • (it's/that's the) story of my life
  • bad company