It's one of the great ironies of life. Think of when people come into Alcoholics Anonymous. Their life is a wreck. Often with work, relationship, legal problems galore. Plus they're an emotional, mental and physical wreck. And that's the critical point at which they need to make their greatest effort to stay sober and turn their lives around.
Or how about stroke victims. Ever go to a rehabilitation hospital? I have for my father. So many people there are elderly. They've worked hard all their lives and now were finally enjoying their "golden years," taking it easy. Then pow! The stroke. Then next thing they know they're thrust into this situation of rehabilitation with physical therapists urging them to make one more rep! C'mon, you can do it!
It's heartbreaking to see. But even in these broken-down, debilitated states people can come back. The same with the alcoholics.
No, sometimes it doesn't seem fair. Like "Life" kicking when you're down. But if you grit your teeth and fight, you can pull out of it.