In any given experience, there is fact and reality, your memories and feelings, and learnings and wisdom. The negative aspects of an experience are easy to focus on and shallow; they’re low hanging fruit. The positive aspects are much harder to appreciate because they’re more abstract, less connected to the facts or your memories and feelings, but are much more valuable.
If you want to improve and learn from your life experiences, you have to allow yourself the perspective to think positively and thus on the valuable learnings in any given experience.