Why does the spirit take on a human form?

I have just been reading the ?organ donation & your soul? thread and it?s got me thinking. I believe the physical human body is just a?..Tupperware container for holding the soul (okay bad joke). After death we are empty and our soul continues on, to where I?m not sure yet. I have told my husband I want to be cremated when I die. I do not want anyone to mourn over my body because it won?t be me, just a broken vessel.
Yet I wonder why when we encounter those who have passed in reality, movies, paintings, books etc they take form in the body we remember and recognize them in. Do you think the physical body carries on with you through after death or is it way of simplifying something that we cant understand?