observing soil

I used to buy gardening soil. I could use it, sometimes gardening went well. Sometimes failed because of sickness or bugs.
I thought this is quite regular way of gardening.

But this time, I took a bag of leaf mold from the park. And I put it in the container, and put more leaves, used tealeaves and coffee. And mixed it.
A month later, I started to use it for gardening. And I realized, this is very different from the soil from the stores.
My plants are happier, no sickness. I don’t need extra fertilizer.
2 months later, I opened my container of soil, and surprised founding so many life, thousand of earthworms and tiny tiny worms, and mushrooms, hyphae. I found this soil is alive. This is why all my plants are healthy now.
The negative thing is, I don’t know how much lives have been lost by being used for gardening.