I know that my time on this earth is limited.
I know that everyone must die.
I should use that as motivation to take advantage of each moment. To appreciate the "small" things.
On second thought, nothing is small, we just ignore the things that really matter. We get distracted.
Entire industries are dedicated toward telling us how to live. what to buy. who to be.
But that's why the contemplation of death is so important. When we understand that our time here is so short, that other stuff won't matter.
What should matter is getting the most out of your life and being the best person you can be. We are all unique, so my best person isn't going to be the same as your best person.
Regardless, we should each try to strive toward becoming our best (or highest) selves. If each of us lived in alignment with our highest selves, the world would be a better place.