Why do I find it more and more difficult to use my brain the way I used to when I was a teenager, it seems short term memory, problem solving and thinking on my feet just isn’t happening the way it used to. Could it be at the tender age of 40 fit and healthy that I’ve neglected to train the intellectual ‘muscle’ ?!
Could well be.
Man, you gotta change your “call sign” first! “Gray”? You’re just reinforcing what you fear! 
One way to look at it is that as each year of our life goes by, we are required to retain more and more information. Kids’ birthdays, SS#'s, phone numbers (home, cell, work, etc.), passwords, drivers liscense numbers, bank account numbers, schedules…you name it.
I think the brain pushes a lot of the “not necessary right now” information to the back, and reserves the rest for vital, important info that we need immediate access to.
But, of course, should you suspect something biological, I’d suggest checking out “Powerdrive” by clicking on the “Store” icon to the left!
mt brain just wasn’t as full when I was a teenager as it is now…
Try reading the books “How to remember names” by Dr. Thomas Crook and “Improve your memory” by Ron Fry. Both these books give an explination, although brief, on why it gets harder to remember and recall information. They also have some useful ‘memory muscle’ training.
Ginko Biloba.
“Gingko Biloba. It helps my memory. I forget what else.” – Billy Crystal, Analyze That
I love that line.
You probably don’t use your memory as much as you used to, and thus it’s out of practise. Think about it: how many phone numbers do you know right now? Your own, maybe one or two more. Everything else is in the cell-phone’s memory, not yours. But ten years ago, you probably had at least a dozen that you could call up at any given time.
The more you rely on machines, the less well your own machine runs. (And yes, I just came back from seeing T3!)
A variety of mental exercises and games are good. It is found that mental deterioration can be delayed, and prevented through use of your brain.
For memory, pick up any Harry Lorayne book. You could easily find one cheap at a used bookstore. Many magicians use his techniques, so I know they work. (Ok, I haven’t used them myself, but I plan on it.)
And Powerdrive. (Ditto)