When I climb into my car I enter my destination into a GPS device whose spatial memory supplants my own. I have photographs to store the images I want to remember books to store knowledge and now thanks to Google I rarely have to remember anything more than the right set of search terms to access humankind's collective memory.
I'm carded for R-rated movies. And I get talked down to a lot. When I try to go rent a car or buy an airplane ticket or other stuff adults do I get 'Okaaaaaay honey.' I remember when I was 18 getting crayons in a restaurant.