I do not have arthritis in my knee!

I am so happy. I have no bone to bone contact. If I did I would be in great pain because as I walked those two places that touched would be oh so painful.  But since i don't have that problem I don't have to hear kind-hearted people give me grossly illogical ways to "exercise" my knee so the hole in the cartilage would go away. Its good not to have it so I don't have to listen to such crazy talk.
I think maybe the doctors have mislead the public in that regard telling them all the best thing for a arthritic knee is "exercise" without defining the purpose or the mechanics. They are almost always talking about exercise of the knee not exercise of the arthritic contact. They are telling them that they cant sit around and let the knee atrophy. They need non-weight bearing exercises like swimming or slow bicycle riding or some other exercise that keeps the knee moving and work the surrounding muscles. See? it's called exercise for the "knee" not exercise for the arthritis.

Ok so I dont have to worry about that. I dont have it. The reason I dont have it is my knee has been removed. before removal here as a scope of my knee that identified places where my cartridge was missing and the bone was touching the bone. I think it is the brownish area in the images below.

So the doc cut it all out and put in a plastic steel replacement as shown below
http://www.biomet.com/orthopedics/video/oxfordAnimation/oxfordAnimation.html

So anyway I dont have arthritis (now) and I am sure I have saved myself a great amount of pain by not listening to well meaning friends and relatives offering wonderful exercise ideas for me. They mean well but...