One of My Theories On Character Growth

One of my favorite things about writing is watching the characters change and grow over the course of the book. When my stories start, neither the hero nor the heroine could form a lifelong bond with someone else, but by the time I near the end, they've changed enough that they can have their Happily Ever After (HEA).

I don't believe that one person can change because of another--not in real life and not in fiction either. I heard someone use this analogy: A person is like a locomotive. You c...