I found this so amusing that I nearly snorted when I read it. Life is a mixed metaphor. Ha! Good one.
It stands to reason that we learn from our experiences and the things we define as "mistakes of the past" are typically the best we knew how to do at the time. We only fail ourselves when we know what we can do and choose to do less than our best. And if we can somehow learn from this, and commit to choosing our own best each and every time, then even that is no longer a failure.
I don't know that Marya, in Quartet, is fully culpable for her victimization. While one might hope that she would have been suspicious of her husband's actions, his arrest merely wakes her up to her reality. The choices she then makes are desperate, no doubt. Her continued reliance on her husband's wisdom also suggests that she is not heeding the obvious. What comes of his arrest is as much a result of her being a victim of circumstance and the conditions she creates for herself.