Does it serve any purpose to complain about things you cannot change? So why would you want to waste your time doing it?Does it serve any purpose to fill your thoughts with regret and resentment over what happened long ago? So why would you waste even a single moment on such a negative, unpleasant pursuit?
You're far better off doing something that does serve a purpose. You're far better off using your time and energy to learn, to create, to love, to understand and experience life.
Your thoughts and actions are immensely powerful. Rather than using them to hold yourself down, put them to work on a valuable and positive purpose.
Use your energy to serve a positive purpose, and as a result you will have even more energy. Fill your time in the service of a positive purpose, and your life will be filled with truly meaningful treasures.
Choose the thoughts and actions that serve a purpose. And life will serve you its real rewards.