How the mind works. We perceive the world as a sequence of visual panoramic bitmaps and our mind constructs a mental map of things with boundaries from these inherently meaningless blobs of color.
Babies work hard to put together a mental picture of what things are and how they work. I saw a documentary about babies that said they sometimes pour liquids on the floor to watch and learn about the fascinating phenomenon of gravity.
I don't remember if that's exactly what the documentary said, but that's my point. We compose a complete understanding from fragmentary sensory input.
My favorite thing about how my mind works is when I've misplaced my glasses or keys and have searched everywhere for them. Sometimes a picture forms in my mind of where I put my glasses down, and I go to that shelf or table or appliance top and sure enough there they are.
So I think that memory is stored in terms of sensory perceptions. I can remember the smell of roses in the neighborhood when I was a youngster.
An example of how people fill in the details of missing pieces with what they expect is that only recently did I realize that English was not my mother's first language.
This is not a trick statement where I was adopted or raised by an aunt. My mother was the child of immigrants from Russia (Lithuania really) and I remember when she would talk to her sister on the phone, sometimes they would start talking excitedly in Yiddish.
So it dawned on me that Yiddish, the common spoken language of European Jews, had not only been my grandmother's only language, but also the language my mother and her siblings first spoke until they went to school.
I knew she spoke some Yiddish phrases and would sometimes tell us a Yiddish proverb or expression, but I didn't realize until very recently that that was her first language and English came later.
It dawned on me recently that my last name of Avrashow must've originally been Avrashoff or Avrashov. And indeed a Google search showed that there are people with the last name Avrashov.