“Life energy” is a term or concept that is introduced in (Chapter 2 of) Your Money or Your Life by Joe Dominguez and Vicki Robin. Simply put, when we spend time for something (money, for example) we give up time to do it. The effort and time spent is life energy. So if you are spending spending time – past, present and future – unwisely, you are wasting your life away.
My definition of time:
Past time: Time that you cannot claim because it’s gone. The only way to show something for it is what from what you currently ‘own’ from your past efforts.
Present time: The now. It will be gone before you know it, and you will know whether you wasted it or not when you need to show what you have from the past at a future point in time.
Future time: It is yet to come. However, you can decide now how you want to live/spend that time.
Parallel#4 is to analyze how you spend your money/time. When you play (competitive) Chess, you record your moves. Serious players go home and play through the recorded game. They can then tell if they missed an opportunity to win more quickly. If there are some mistakes that they made and they should learn from and not repeat. This is an example of analyzing the past time in the present time to affect the future time.
Analyzing your expenses will show you how you are spending money. This money is what you gave up your life for (at work). Whatever you buy with that money is worth your life. Now, THINK: what are you giving up your life for?