After two months of bike limitation and physical therapy, I'm told by another doctor that I probably do have arthritis after all, and "there's not much we can do about it." ...For a couple of months, I had hope, and now it's been taken away.
I pushed on the idea of cartilage-like injections to my knees, and the doctor agreed to do some MRI's and some treatment (if the MRI merits it).
I've ridden bike all these years to keep things limber and fluid. I'm not going down like my mother, my grandmother, and my great-grandmother. I will not spend the majority of my life in a crippled state. I will not come home crying after the doctor's diagnosis. I am going to win on this thing. Dammit!