A few years back, I was following a friend's father through a parking lot as he was trying to take his sweatshirt off. In the process, his shorts fell down.

"Getting old sucks," he said.

Aging does sometimes seem that way. But it's not just your pants you stand to lose--all too many elderly people have lost their memories. Some studies estimate as many as 50 percent of people over age 85 have some sort of Alzheimer's-related memory impairment.

But even old people who don't have Alzheimer's experience what they jokingly refer to as "senior moments"--times when their mental pants fall down and they can't remember a telephone number, where they put their keys, or even where they parked their car.

Is this inevitable for all of us? Is there a time when our brains won't be able to take in new information and form new memories? Or are there things we can do to keep our brains young?

Although our brain decline, like other forms of aging, begins when we're in our 20s--gasp!--the news on this front is surprisingly good.

Old brains can learn new things--and in some ways, they can deal with information even better than young ones.