Motivating Yourself: Facing a Difficult Challenge

Have you ever faced a challenge to improve something about yourself after years of tolerating the problem? Suddenly you have an opportunity to make the change - but now you are trying to decide if it is worth the effort that will be involved? What made you decide the effort was worth it, at least enough to take the first step? Please share how you motivated yourself to start, and to continue the process! How did you deal with any setbacks, and what was the challenge you were overcoming? I will pass on your responses to someone who is trying to make such a decision now, and who might welcome words of wisdom from people who have already successfully tackled their own challenges (or are in the process of doing so).