Feeling my age

I went to the doctor last week, for my semi-annual checkup (I see the endocrinologist twice a year to keep tabs on my thyroid). I told her I was having some stiffness in my right knee and she said, "Well, you're getting arthritis." Wow, those are words that make you feel old. I just celebrated my 46th birthday - hardly over the hill. But last year I got bi-focals, and now this. It's officially downhill from here.