When your mind thinks about the past, it will always associate those memories with the emotion(s) associated with the event. So what happens is, you condition yourself to think about memories that do not serve you because they are negative. Negative thoughts (memories) create a negative environment.
Your mind will focus on what’s familiar to it.
Therefore, you are essentially reliving the same negative event over and over.
You think about a difficult event in a previous relationship >> you get upset because the situation made you angry and sad >> you spend the next couple of hours relieving those same emotions, even though it already happened >> the cycle continues
Some people do this for days, weeks, months, years, and even their entire lifetime.
A visual representation of what happens when you allow your mind to take control of you.
You must learn to break the cycle and master yourself. Learn to control what you’re thinking about, aka “observe” what you’re thinking about. If these memories do not serve you, let them go. You can’t change the past but if you’re not careful, you can take your emotional response with you. Is that how you want to move forward? My guess is: no, it does not serve you or anyone within the circle of your influence.
Focus on thoughts (memories) that will set you up to win. If you want to win the day, master yourself. You are worth it.