I was asked this recently, and it is one of those questions that I get often. I feel differently about all of the pictures I've taken and been pleased with; it's difficult to narrow down a single photo as an absolute favorite. It feels somehow unfair. That being said, I do have a picture that is my favorite. And that troubled me for a long time.
I will never be able to replicate this picture; the time and emotional place are just as important as the physical location. That's the reason it's my favorite. However, until recently I felt that it limited me, which is why it troubled me. "Surely, nothing I experience will ever match that day...so no future photograph will ever measure up." Rather than choosing a limited view, that same understanding can open me up for greater success. I will never take another picture like that again, but I can seek completely different images to express myself. Acknowledging that I will not be able to replicate that image will stop me from trying...and move on. Trying to re-create a "better" version of that picture is a waste of time and resources.
This same process is helpful in a variety of areas in life. No two books are the same. No two relationships are the same. No two jobs are the same. The longer we hold on to the feeling of, "This is what I've experienced before, and this is what I need to achieve again," the longer we rob ourselves of new and potentially greater experiences. I encourage you to look around and see if there is anything you are trying to 'recapture' from the past; it could be limiting you from even greater heights in the future.