Thanks for picking that statement out. I noticed it and thought about its relevance in other areas of life as well.
By repetition, habits are formed. Desires are reinforced, tastes are developed. How many people who smoke cigarettes really liked the first one (or first pack)? How about alcohol? Many vices (I consider smoking and drinking vices, pick your own habits here) have to be learned and you almost have to "force" yourself in the beginning.
Habits create subtle (and maybe not so subtle) "grooves" in the brain. Brains actually change depending on what we do. We remember past pleasures, shames, guilts, fears, emotional reactions, and they mold future choices.
An ounce of prevention is worth a pound of cure; but if we want a cure badly enough, we'll be willing to do what it takes to make the cure. I've been around the block (more than once) and have unlearned a great many vices and bad habits. We can become new. Our hearts and minds can change, and we can become the servants God wants us to be. It's not that we become something different, it's becoming more who we really are.