We can't avoid every potential mistake because we are humans and flawed (and/or inexperienced or immature or...). Yes, mistakes do engender sorrow -- but mistakes and sorrow are a part of life. What I tell friends is "Yes, we learn from mistakes -- but I'd like to learn not by making mistakes myself but by learning from others' mistakes as much as possible first." A corollary is that others may know or be honest with themselves less well than we know and are honest with ourselves -- so any relationship has its vulnerabilities. The best we can do is to try to better ourselves -- and associate ourselves with others who are doing the same.
Everyone suffers from some level of intellectual and emotional and spiritual disintegrity. The best we can do is to seek and cooperate with the Lord's healing in such things.
We are all in a way complicit in everything because we are a society. So we are all in a way responsible for helping and fixing everything -- to the degree that we can. The buck stops when another person says "I choose not to change for the better."
Everyone wants to be married. The discerning line is between desperation and prudence. The first brooks no delay, the second allows for it. Prudence is the beginning of wisdom. Just being aware of the personal and societal need for sanity is probably what keeps most of us, and society, sane.