None of us go out there intending to make a mistake. We make choices based on the information we have and with the best intentions for our own well-being.
Sometimes it works out, and sometimes it doesn't. It's that second outcome--the 'doesn't' bit that throws us for a loop, that signals to our already-over-sensitive conscious that we *should* have known, we *should* have had some kind of intuition, or if we had just thought things through a little harder, a little more thoroughly, a little more holistically, that we'd have reached a different conclusion.
Well, we can hypothesize and rehash all we like, but not only does it change nothing, it doesn't make us feel better and it's a fruitless exercise in needless self-harm. We couldn't have known better. If we had, things would have been different. It's so hard. Life can be so hard, petals--but we do the best we can with the information we have. We do. We have good hearts; we have good intentions, but sometimes the world has other plans for us.