I think those "vacant lots" increase with age as we try to maneuver around them. And, not remembering something isn't so bad if we can remember it before we try to go to sleep and it worries us all night.
Eh..what did you just say? It must have been good because after I read it, I started to write. Oh yes, now I recall, it was about forgetting stuff after all. I knew it, I knew it, and you got it right. Were all afraid of forgetting and loosing are marbles somewhere in the night...
Ron