Meerkat you always make me smile, my patella being 'nibbled' away is just about spot on. The strange thing with my knees is although I've had discomfort and the obvious feeling that something wasn't right, i've never had any real pain.
Happy Birthday Meerkat. Although I've only been running for 10 months I've had minor knee problems through years of tennis on hard courts. Running seemed to really highlight the problem. After being told I had a torn meniscus and not believing it I had an MRI scan, showed no tear but grade 4 chondromalaecia patellae (sp!) which I think is the worst grade. I was recommended a Sports Physio in Stockport (Sports Med) they were brilliant, after about 4 treatment sessions (heat, ultrasound, massage, faraday machine) and being totally disciplined about doing the quad strengthening exercises, I now have almost no problem with my knees, I know they will never be like they were 20 years ago (I'm 50 by the way) but I would never have believed they could have improved so much from a few months ago. My knee advice is find a good sports physio with a very positive 'can do' attitude.