they say that memory training can slow down this sort of thing
- or the equiv - crosswords, soduku, learning a language .....
( but the difficult is that the people doing those brainy things may not be the set who are gonna have memory difficulties )
the sign you are describing is called
thingey - that one - hoo-jumma-flip ( yeah sorry we have already had that one)
nominal aphasia -
https://en.wikipedia.org/wiki/Anomic_aphasia
v v common
I forgot a colleagues wife had died the year previously once
very very embarassing .....