I have to write things down which I need to do - but I put that down to having so much in my head (work included) that I can't possibly remember it all otherwise. I have to take a shopping list with me, I can't manage without.
However, I do have a long-term memory too - I remembered the name of a neighbour from 20 years ago the other day - it dredged up from somewhere in the depths!
I think it gets harder the longer we live, as we add more memories all the time and the brain has to sieve out what's important, and archive the rest.