Answer:
Although a human shape I wear Mother I never had; And though no sense nor life I share in finest silks I'm clad. By every miss I'm valued much beloved and highly prized; still my cruel fate is such by boys I am often despised.
I am a portal to another world which you cannot enter. Only you can see me but I can't see you.
I have wheels and flies yet I am not an aircraft.
I am in the past, never in the future. I don't exist, but have existed. I saw what you saw, and this is what I will ever see. What am I?
When you take away the whole from me there is always some left.
When someone uses this acronym, you know you've got to pick up the pace