A tanning plateau

Is it possible to lose tanning ability with age?  When I was younger, teenage years through my 20's, I had no problem baking in the sun. I would lay out for hours and come in with a nice bronze hue.  Occasionally, a few "red" tans would appear {yes I see a dermatologist},  but they would always turn bronze in a day or two. And I would tan evenly. Arms and legs at the same time. But now, this is how I tan:

 Give me a break! I can't tell if that's my leg or the carpeting.  :)