There is hardly a more bitter disappointment and injustice shock than when you realize that every time you move forward you will inevitably feel like a 1st grader starting grade 2.
Remember when years ago, right after you nailed multiplications they introduced algebra & geometry? Same with situations and people being given to you throughout your journey. Never the same challenge, the same exact lesson.
The only difference between life journey and formal school is that the number of grades we complete depends on our choice solely. And yes there is no diploma. The ultimate appreciation comes only from ourselves and how much time we have been content with our own progress.