The act of humiliating someone who thinks they are high and mighty. Taken from the following occurrence: A boxer bragging and smirking at a dive bar; a midget shredding his legs below the knees with his shiv.
"That neo-Nazi cracker has not been so boastful since that little Jewish girl cut his knees out."
From me eyes deh at me knees means since someone was a kid. Literally since their eyes were at their knees.
I've been hearing about that old man from my eyes deh at me knees. This expression paints the picture of how you have grown a lot, comparing the height you were as a kid to how you are now.