"We create our own demon" what does it mean in real life as dialogue in "Ironman 3" movie?

“We create our own demons,” So I just watched Iron Man 3 thought I could share this with you guys...
Tony Stark begins in Iron Man 3, in a cliche and yet inspiring opening. Oscar Wilde once said, “We are each our own devil, and we make this world our hell.”. Damn true. We should hold responsibility for what we have done and the consequences that follows.
Wuthering Heights, produced by BBC in 2009, is one of the adaptions Emily Bronte’s novels of the same name. Tom Hardy, the Heahcliff, is the one that struggles his whole life till death for the love of Catherine. The desperate love reminds me a paragraph from “The Thorn Birds” by Colleen MacCullough,
“Each of us has something within us which won’t be denied, even if it makes us scream aloud to die. We are what we are, that’s all. Like the old Celtic legend of the bird with the thorn in its breast, singing its heart out and dying.”
Love and hate. Love becomes hate when it is twisted and filled with obsession, betrayal and redemption. Sometimes, we do things, terrible things, in the name of love, which is only the excuse that we made to justify our behavior.
“The mind is its own place, and in itself can make a heaven of hell, a hell of heaven. Nature has placed mankind under the government of two sovereign masters, pain and pleasure – they govern us in all we do, in all we say, in all we think: every effort we can make to throw off our subjection. Maybe half of it is what we consider as hell. You go mad, and all your demons come and get you just as fast as you can think them up. Vicious habits are so obnoxious and degrading that they transform the individual who practices them into an incarnate demon.Sadly.
We can decide to confront the dark parts of ourselves, and work to vanish them with illumination and forgiveness. Or better yet ameliorate the high ethical standards we already acquire that are essential to good character. Our willingness to wrestle with our demons will cause our angels to sing instead.
It would rather be an inspiration rather than a fiendish. To do good is effortless but doing the opposite requires conscious exertion of pain, of trouble.”
https://www.quora.com/We-create-our-own-demon-what-does-it-mean-in-real-life-as-dialogue-in-Ironman-3-movie