Albert Einstein once said "No structure is stable".
He never mentioned the structure of the triangle. The triangle is the most power natural occurring shape.
Like in the famous game, Zelda power, wisdom, and courage of the Triforce 
We say mind, body and spirit are the best ways to live a balanced life.
There's the past, the present and the future. The past brings depression of reflecting on the past mistakes, the present is in the moment, the moment of serenity and is usually seen as the euphoric and last we have the future which brings anxiety or fear of the future and unknown.
There was actually a study showing that your thoughts can active different DNA in your body, activating or deactivating diseases. https://www.scientificamerican.com/article/changing-our-dna-through-mind-control/
We have three different sleep cycles, our brains are split up in threes, three dominant desires from the reptilian mind which is eat, sleep and reproduce(https://steemit.com/psychology/@v3n0mmang/the-reptilian-brain-in-all-of-us).
I recommend a few different books that'll explain how to live a more balanced life style.
Think and Grow Rich - Napoleon Hill
Maximum Achievement - Brain Tracy