There are so many great songs to pic from. And I only listen to music that I love the lyrics as well as the rest. But this popped into my head when I read the question so I am going with Nine Inch Nails - "Right Where it Belongs".

See the animal in his cage that you built Are you sure what side you're on? Better not look him too closely in the eye Are you sure what side of the glass you are on? See the safety of the life you have built Everything where it belongs Feel the hollowness inside of your heart And it's all... right where it belongs

What if everything around you Isn't quite as it seems? What if all the world you think you know Is an elaborate dream? And if you look at your reflection Is it all you want it to be? What if you could look right through the cracks? Would you find yourself, find yourself afraid to see?

What if all the world's inside of your head Just creations of your own? Your devils and your gods, all the living and the dead And you're really all alone? You can live in this illusion You can choose to believe You keep looking but you can't find the woods While you're hiding in the trees

What if everything around you Isn't quite as it seems? What if all the world you used to know Is an elaborate dream? And if you look at your reflection Is that all you want it to be? What if you could look right through the cracks? Would you find yourself, find yourself afraid to see?