Slavoj Žižek said this quote

We don't really want to get what we think that we want.I am married to a wife and relationship with her are cold and I have a mistress. And all the time I dream oh my god if my wife were to disappear - I'm not a murderer but let us say- that it will open up a new life with the mistress.Then, for some reason, the wife goes away, you lose the mistress.You thought this is all I want, when you have it there, you turn out it was a much more complex situation. It was not to live with the mistress, but to keep her as a distance as on object of desire about which you dream.This is not an excessive example, I claim this is how things function. We don't really want what we think we desire