Aging is a topic I very interested in, obviously, as I am accumulating years of living and experince myself. However, I have been observing a phenomenon with people as they become older - that becoming older is also, and for me mainly, a state of mind. Physical problems all of a sudden are associated with age, though younger people might have the same kind of problems. Being tired is all of a sudden associated with age, when earlier it was stress or work or.... whatever, but not age.

About the slower memory, well, I like the metaphor I once read  - the mind is like a computer, when its new it is fast retrieving information, but as you save more information on the hard disk, it takes longer to find the it again. I like to think that the mind functions the same way and that taking longer to remember something is a sign for a much vaster database that has to be searched. :-)

Oh, and I am aware that I am kidding myself to a certain degree. But I also firmly believe that our thoughts and expectations do have a tendency to be self-fullfilling.

To repeat, I consider age primarily to be a state of mind, and one sign of aging for me is the refusal to learn new things - for example, many of my friends refuse to learn about computers, or new languages or... because they are now of a certain age. Age also becomes an excuse. So, definitely, according to my definition you and PerCLupi are still youthful, as you are open to new and challenging experiences - like posting here on ET. :-D