A few lines from the Yoga Vashishta:

Everything in this world is dependent upon the mind, upon one's mental attitude.
On examination, the mind itself appears to be unreal!
But, we are bewitched by it.
We seem to be running after a mirage in the desert to slake our thirst!
Sir, surely we are not bond slaves sold to a master; yet we live a life of slavery, without any freedom
whatever.
Ignorant of the truth, we have been aimlessly wandering in this dense forest called the world.
What is this world?
What comes into being, grows, and dies?
How does this suffering come to an end?
My heart bleeds with sorrow, though I do not shed tears, in deference to the feelings of my friends.