Pink Floyd -Wish you were here

so, so you think you can tell
heaven from hell,
blue skies from pain.
can you tell a green field
from a cold steel rail?
a smile from a veil?
do you think you can tell?

and did they get you to trade
your heros for ghosts?
hot ashes for trees?
hot air for a cool breeze?
cold comfort for change?
and did you exchange
a walk on part in the war
for a lead role in a cage?