So long as you don't dwell on the (unchangeable) past, you can actually learn a lot from negative experiences, especially when you realize you have reached an inflection point.
An inflection point is a place where there is no tangent to the line. In other words, you can pick almost any direction. But this infinite array of choices can be debilitating if you don't edit your choices. This requires a good deal of critical self-reflection, and this is the subject of Howard Stevenson's lesson on Big Think Edge, the only forum on YouTube designed to help you get the skills you need to be successful in a rapidly changing world.
Being honest with yourself - or not cheating at Solitaire, as Stevenson puts it - is essential because "many people have a notion of themselves that’s not borne out by the facts."