WHERE DID I PUT MY KEYS?

If you're north of 40, this may be a familiar refrain, right along with "Where's my wallet?" A health writer of a certain age digs into what's normal, what's not, and how to shore up your memory.

- AMY CONWAY

RECENTLY, A middle-aged friend of mine joked that he doesn't need to buy any more novels-he barely remembers the ones he's already read, so he can just pick one off his shelf and start fresh. Another friend had to do calculations to figure out whether she was turning 52 or 53 (or maybe 54?). We're at the stage where we're forgetting names and looking for the reading glasses that are on top of our head.

While we're laughing, we're also wondering: Is this something I need to worry about? After more than a few of these discussions, I started to dig into the research and talk to some experts. I am a health editor, after all, and at this point in my life, a lot of my work starts with my own aches and pain points-physical and mental.