In the process, and not until the very intense turning point, he realizes that by constantly re-living the event, he has recreated it in his current life.
Koontz is a master storyteller and has the talent for deep thought, and for creating huge "WOW" moments in his stories. Here's the WOW I took from the book: We miss the joys of the current moment, and we attract the trauma or sadness or mishap, every time we relive unhappiness in our past.
As you'd know by now, I'm a firm believer in Law of Attraction and have had miracles in my life from this mindset, so Koontz's moral doesn't come as anything new to me. But in the subtlety of the lesson throughout the whole book, I realized at the climax of the story that I'd missed this main point. Perhaps Koontz meant for that to be the case.
Only light can cast out darkness. And by focusing on light in this, the present moment, we let go of any darkness that tries to keep hold. I know this from my own life. Learn to let go of any darkness in your own past in whatever way is healthy for you, so that you can clearly see the light, right here in front of you.