How come when someone suffers from amnesia they still remember how speak, read, write, etc.?

At least that's how it's portrayed in the movies. Is it like that in real life?How come when someone suffers from amnesia they still remember how speak, read, write, etc.?
Speech , writing and reading are all SKILLS , rather than memories . Just like how to walk , how to drive a car or a bicycle .

Skills are stored on a lower , less conscious level than abstract memories .

However , in some brain lesions one DOES forget how to write for example , it's not so much forgetting as it is "failing" to perform .

Different information are stored in different segments of the brain .How come when someone suffers from amnesia they still remember how speak, read, write, etc.?
What Amnesia does is affect how the victim remembers events in the past, or memories. It can also spread so the victim can't remember certain things such as family, friends, daily routines, etc. From what I have heard, Amnesia victims normally recover from this illness, but it can take a long time.