s'funny, I actually knew what it meant... I say it all the time, but the context threw me off. The OP made this sound like a irrevocable permanent cliff dive they are careening toward.
I thought "oh god is there some new hell I need to look out for?" and immediately forgot everything I know. Bad brain, no cookie.
My advice is for what I do for me or my son when head for that wall: Don't fear it, manage it if you can, prepare a safe landing place if you can't. Worrying about the potential of it happening seems like a self fulfilling bad idea.
Still I didn't realize that episodes of burnout could be as dramatic and long lasting as it sounds like they can be... though... I would still avoid worrying about it to much... stress ABOUT stress is cyclical and horrible.