Often times, people ask the hypothetical question, what would you do if you could go back in time? What would you change? My answer: nothing. While admittedly spurring out my drunken words this Saturday night, when asked this question, I think my profound subconscious came out in the height of my intoxication. While I may think of a few things that I would like a different outcome to, I began to realize that at this moment in time, I am where I'm supposed to be, and I always will be. Anywhere I am is where I should be at that moment, the universe makes no mistakes.
Of course, your decisions affect things that occur in the future, we learn from the choices that we or others make within their life. Failure is an ambiguous term, you only can fail if you didn't learn from your mistakes. If you are never facing the consequences of your choices, if you never learn from your past mistakes, how can you build wisdom for the future?
The person you go to for the most advice has likely been through a situation similar or they have the life experiences to help them give advice. Maybe you're stuck in a less than ideal situation, but then you can find out how to avoid the mishaps the second time around as well as help other people. Everyone who comes and goes in your life will teach you something new about yourself and others. This means that no one is a waste of time, even people who hurt you will teach you how to deal with those situations in future interpersonal relationships.
Although you may not be able to acknowledge someone's prevalence in your life as of now, in the future you may realize that through terrible situations comes wisdom. This is why it's important to let go of hate, even for that friend or relationship you thought of as a waste of your precious time. Think of every person who leaves your life as a new open door, a bridge to knowledge. Sometimes it's necessary to nostalgically dwell a little on the past, it teaches you more about the future than you can ever now. This is how you can let go of your anger about past relations with others, this is how you can mend present and future relations. What do you think, if you could change anything that happened in the past, would you?