Answer:
The man who made it didn't need it. The man who bought it didn't use it. The man who used it didn't want it.
What can't you see, hear or feel, until its too late. What shadows love, and shopkeepers hate?
Half-way up the hill, I see you at last, lying beneath me with your sounds and sights. A city in the twilight, dim and vast, with smoking roofs, soft bells, and gleaming lights.
Upon me you can tread, though softly under cover. And I will take you places, that you have yet to discover. I'm high, and I'm low, though flat in the middle. And though a joy to the children, adults think of me little.
A dagger thrust at my own heart, dictates the way I'm swayed. Left I stand, and right I yield, to the twisting of the blade.
I never sleep yet sometimes I weep. I can get angry or just be happy. Wherever you go, I will follow. No matter what you do, I will be there. I cannot die. What am I?