"Remember that I am thy creature; I ought to be thy Adam, but I am rather the fallen angel, whom thou drivest from joy for no misdeed. Everywhere I see bliss, from which I alone am irrevocably excluded. I was benevolent and good; misery made me a fiend. Make me happy, and I shall again be virtuous."
and
"How can I move thee? Will no entreaties cause thee to turn a favourable eye upon thy creature, who implores thy goodness and compassion? Believe me, Frankenstein, I was benevolent; my soul glowed with love and humanity; but am I not alone, miserably alone? You, my creator, abhor me; what hope can I gather from your fellow creatures, who owe me nothing? They spurn and hate me. The desert mountains and dreary glaciers are my refuge. I have wandered here many days; the caves of ice, which I only do not fear, are a dwelling to me, and the only one which man does not grudge. These bleak skies I hail, for they are kinder to me than your fellow beings. If the multitude of mankind knew of my existence, they would do as you do, and arm themselves for my destruction. Shall I not then hate them who abhor me? I will keep no terms with my enemies. I am miserable, and they shall share my wretchedness. Yet it is in your power to recompense me, and deliver them from an evil which it only remains for you to make so great, that not only you and your family, but thousands of others, shall be swallowed up in the whirlwinds of its rage. Let your compassion be moved, and do not disdain me. Listen to my tale; when you have heard that, abandon or commiserate me, as you shall judge that I deserve. But hear me. The guilty are allowed, by human laws, bloody as they are, to speak in their own defence before they are condemned. Listen to me, Frankenstein. You accuse me of murder, and yet you would, with a satisfied conscience, destroy your own creature. Oh, praise the eternal justice of man! Yet I ask you not to spare me; listen to me, and then, if you can, and if you will, destroy the work of your hands."
-The Monster to Frankenstein, "Frankenstein; or, The Modern Prometheus" - Chapter 10
"Civilized men are more discourteous than savages because they know they can be impolite without having their skulls split, as a general thing." - Robert E. Howard, "The Tower of the Elephant"
"Every man has to go through Hell to reach Paradise" - Max Cady, "Cape Fear" (1991)
"Mental toughness is the ability to accept the fact that you're human and that you're going to make mistakes - lots of 'em- all your life. And some of them are gonna hurt people that you love very badly. But you have the guts to accept the fact that you ain't perfect. And you don't let your mistakes crush you and keep you from doing the very best that you can." - Billy Jack, "Billy Jack" (1971)
"Don't ever think that the reason I'm peaceful is because I don't like to be violent." - unknown (meme I found online some time ago)
"The successful warrior is the average man, with laser focus." - Bruce Lee
"Where is the Life we have lost in living? Where is the wisdom we have lost in knowledge? Where is the knowledge we have lost in information?" - T.S. Eliot
"Why waltz with a guy for ten rounds if you can knock him out in one?" - Rocky Marciano
"If they stand behind you, protect them. If they stand beside you, respect them. If they stand against you, defeat them." - unknown (a meme I found online some time ago)
"If the prospect of living in a world where trying to respect the basic rights of those around you and valuing each other simply because we exist are such daunting, impossible tasks then what sort of world are we left with? And what sort of world do you want to live in?" - Wonder Woman, Wonder Woman #170 (so says the meme anyway)
"Momster": What happens to Mom after she counts to 3..." - unknown
"Fate whispers to the warrior 'You cannot withstand the storm', and the warrior whispers back 'I am the storm.'" - unknown (meme I found online some time ago)
"I got some bad ideas in my head." - Travis Bickle, Taxi Driver (1976)
https://www.youtube.com/watch?v=Zh_k81GI8G4
And one more that is very much Ravenloft-appropriate (imo):
"Whatever comes our way, whatever battle we have raging inside us, we always have a choice. It's the choices that make us who we are, and we can always choose to do what's right." - unknown (a meme I found online some time ago)
There are a ton of others but with more of an "R-rating" that's probably best to not drop down in here.