However, in effectively all my personal relationships, success correlates strongly with magnitude of desire.
I wholeheartedly disagree.
What separates success from failure is the ability to learn from your failures and to try again. You failed at both so far.
Would you please be more specific?
I don't know the conditions of why you left but assuming it's relevant to the letter then you failed to focus on things that matter like school, family, etc. This is a life lesson that cannot be learned with words alone, family and friends are much more important than money or success, it takes many a lifetime to learn this.