A couple have a baby boy but, to their shock, he is born with only a head. Perfectly functional, perfectly alive, totally conscious, but just a head. They say to the doctor 'Is there anything we can do? Is the science available to have a body attached to our darling son, so he might live a full and normal life?'
The doctor says 'No, not right now. Science is not yet that developed. Maybe in a decade or two? The best advice I can offer is to take your son home, love him, cherish him (even if he is just but a head) and who knows?'
So the couple take their new son (who they named 'Ed') home and raise him and love him, even though he's just a head. It's not the easiest life for them all, but they get by.
Eighteen years later, (on Eds birthday) the Doctor calls back. 'Hi, guess what? The science is now available! We can give your son a fully functioning body! Bring him over here as soon as possible!'
The parents weep with joy and go into Eds bedroom, where he is propped up on a pillow, and say the following words...
'Son... you're 18 now. And we are so, so happy to tell you that we can offer you the greatest present you could imagine, something you've been wishing for the whole of your life...'
And Ed says 'Oh Christ... not another fuckin' hat....'