There’s something to say about Rory claiming his own identity and embracing himself as well at the end of Series 5. He fights as hard as he can against the Auton programming: “I am RORY,” he says, prompting Amy to remember him.
Yes, the series arc properly belongs to Amy, who triumphantly claims her past, but Rory’s arc is just as important, I think.
He figures out who Rory Williams is–not just Amy’s boyfriend/fiancee/husband, but himself. He’s already immensely loyal, but he’s super insecure in general (which doesn’t completely go away, but when do our problems completely go away even when we’ve made major breakthroughs regarding them?).
That two thousand years–awake, alert, guarding Amy–means he had plenty of time to think. And at the end of it, he without a doubt knows what his principles are, what he stands for. He can be a nurse, be compassionate, be caring, and unshakeably be that person. He embraces it (as he tells his dad in Series 7, he collects nursing equipment). He claims himself–someone who can wield a sword but prefers to bind up wounds, someone who can speak a compassionate word but can also confront a friend (usually the Doctor), someone who is complex but is confident in that complexity.