I can still remember the address of the house where I lived when I was 6. And the one in my teens. And the last house my parents owned. Even the phone number.
Some of the things I do to keep my brain active is work on jigsaw puzzles (on line, of course) and other activities like crossword and slide tile.
Music is a wonderful tool. I find that if I DO forget something, it's usually when I'm very stressed. Music definitely helps. Especially Mersey Beat music.
I've cut WAY back on watching news because, well, the anxiety issue.
But the #1 thing that keeps me mentally agile is dealing with my fur babies.
One of the major red flags I always watch for is this: My mom had Alzheimer's. Leading up to her diagnosis, and I'm talking several years, she'd always lose her purse in the house. Now, she always put it in the exact same place, hanging on the back of a kitchen chair, but she'd still 'lose' it. As soon as I get home I put my keys right back on the hook. If I start 'losing' them, despite them being where they should be, I'll know something is coming. Now, on the rare occasion if for some reason I set them down somewhere else, I just don't fret and retrace my steps. Bingo. I find the BIGGEST impediment to finding something is frustration.