The way my memory works

Sometimes i remember a problem the same,
but i can't remember a face or a name,
sometimes i see something quick,
then somehow it will forever stick,
occasionally i repeat something i said,
wondering how it all fits in my head,
Serial numbers i can remember too,
but forget the small details about you,
text written in a manual stays,
but a book is gone in only days,
I remember a movie front to back,
but my childhood remains mixed with black,
specs here and there remain,
if i try to remember i just strain,
given time it may all completely fade,
as time goes on slowly it will degrade,
I am working on those weak places,
but i worry if i improve it just replaces.