Is it possible to grasp the idea that every little thing you do impacts the life of someone or something else?

I have been tossing around this idea in my head a lot lately and have only come up with one answer. History repeats itself. Sooner or later...it just does. Lessons are learned, forgotten, and then realized again. It's a beautiful story with many tragic endings. My heart breaks sometimes...then picks back up and sores through the sky. Nothing in my mind comes easy. Everything is questioned and always more than once. This happens usually because it doesn't make sense to me on one hand but on other hand - I can validate the other response. Often confusing - never consistent. It also happens to be one of the beauties in life.