Never again is the catalyst for change. When someone makes that kind of declaration, then it is absolute that whatever it is will never be tolerated again. No one can talk you out of it. It is not up for discussion. The bridge behind you is ablaze so there is no going back.
I am not good at burning bridges, I am good at devising exit strategies, which goes against the never again mantra. It's almost impossible to be full committed in a direction when it's just as easy to turn around and go back. Never again prevents even a glance back. The weight of glancing back is an overfilled backpack, filled with much more than the necessities to proceed. Drop the pack and carry on. Never again makes dropping that excess baggage a must.
Without never again there is very little leverage to change. If there isn't leverage, then you haven't convinced yourself of its necessity. If change isn't a necessity, then it's okay to go on with the way you're living, which may be fine. But if there is something you really want to change, it is imperative to get to the point where you declare: never again!
This is a concept that Tony Robbins talks about, and it is much easier in theory than in practice. I hope to get to that point for a few of my vices one day. What if I ever need that bridge? It takes a lot of strength to burn it down. It's much easier to lightly cover the trail behind and say, "I'll be able to find my way back to the bridge if need be." But at least I have the courage to carry the matches, just in case.