You as humans are creatures of the light. But you need the dark to be healthy and thrive. You must create a balance.
First you must sleep in the dark, dreaming, recharging and renewing your bodies and minds, then waking and soaking in the light, acting, getting things done, creating the life you dream of.
Within this balance of light and dark, action and rest, you find your sweet spot so you can create and sustain a thriving life.
I as a towering cottonwood tree must find my balance between spring growth and winter rest, between roots and branches.

I would not want to topple over in a windstorm for lack of roots, top heavy with huge and heavy limbs. I would not want to waste my energy sending cottonwood sized roots deep and wide into the soil to support a small and modest crown the size of an apple tree.
To be healthy, the Earth and her atmosphere must strike a balance between hot and cold, wet and dry, storm and calm, ebb and flow, flood and drought, summer and winter, health and sickness…