Cynic decry such capacity ("Don't you know that leopards can't change their spots?"). Perhaps this is in part because most people do not change for the better all at once in some sort of Scrooge-like total turnaround.
Instead, we change slowly, from bad to good and from good the better and so forth (sometimes at a glacial pace). Line upon line and precept upon precept is not just the pattern to increase in knowledge and intelligence; it is our most well-trod path toward change.
Following such a path, I may today decide to leave behind my anger at unfortunate events relating to unimportant things (where "I can't believe I missed the *@^&@ train!" becomes "oh well ... more time to read."). Then, later, even unfortunate events relating to important things won't phase me.
With change, backsliding happens. Sometimes its three steps forward and two steps back. And the cynics love nothing more than to see the one progressing fall back (like crabs in a bucket, as my high school English teacher would say).
But progress, however small and incremental, is still progress. As Lorenzo Snow taught:
If the husband can live with his wife one day without quarrelling or without treating anyone unkindly or without grieving the Spirit of God in any way, that is well so far; he is so far perfect. Then let him try to be the same the next day. But supposing he should fail in this his next day’s attempt, that is no reason why he should not succeed in doing so the third day. ... Do not expect to become perfect at once. If you do, you will be disappointed. Be better today than you were yesterday, and be better tomorrow than you are today.
The key is not how far along the path we are nor the speed at which we're traveling, but the direction we're traveling.
And so it is that I tell myself to keep going. No matter how hard or how often I want to give it all up, keep moving.
Change will come.