I am a human head

I'm a human head
And my best friend is also a head
I don't really need my best friend

Now my friend is gone
And I'm only a head by myself
I find I don't need my whole head

Now I'm just the top of a head
Just the scalp and the hair
I don't like the scalp, just the hair

What do I really need?
Best friend, also a head
Just the head, just the scalp
Hair

Friend, no
Head, no
Scalp, no
Hair

I am only one human hair
With no scalp for a home
All I need's the top of a head

Now all I am is just a skull
I don't have any head
I'd be glad if I had a head

Now I have a head look at me
I'm a fine floating head
Where is my friend, the other head?