Here are some of my favorite jokes about getting older and memory. These are all mine, by the way.
I'm getting older but I'm not worried about losing my mind some day. That ship has already sailed.
Actually, it's more like it sailed, caught fire, sank, and is now an artificial reef.
I'm not the sharpest butter knife in the drawer anymore.
When I was younger I had all kinds of thoughts running through my mind. These days it's more like a slow crawl.
I'm a fairly existential thinker. Sometimes I stop and ask myself, "Why am I here?" Fortunately the person ahead of me in line usually knows.