What is renunciation?

What is renunciation? If we are always thinking of suffering and impermanence, maybe it is going to be difficult to motivate us in our practice. So, what do we do? We must understand that renunciation is knowing the true nature of this world. What we must really understand is what is the true nature of suffering  and what is the true nature of happiness. This is renunciation. What are we renouncing? We are renouncing our misunderstanding, our ignorance and then, wisdom arises through the veil of ignorance.