You Have a lot of Gall
Not me since I had my gall bladder removed earlier this year and lost 30 lbs. Here is my one and only proof, other than the mounting hospital bills.
I wish I had gall, and since the gall bladder contains bile which I'm told is very bitter that gives rise to the use meaning "you've got a lot of bitterness/rancor". And as one of my neighbors like to say "In any event".