By using the advantages of different plants you are able to grow eatable plants like zucchinis, tomatoes and arugula without using chemicals. Trees give shadow, copse gives living space for useful insects, compost gives nutrients...
By simplifying the term of permaculture you can say that it´s the principle of life. It needs more work to cultivate permaculture on your land, but it comes up with higher crops per hectare and sustainability.
Do you remember when you let snails crawl on your hands when you were a child? It was a fun experiment, but you and your friends only did it once because it was so hard to wash off the yucky slime afterwards.
I´m sure that you´ve been in the situation before: you were really stressed out and then you ate something in a hurry that made your stomach go loopy. Usually you can handle the simple sugar, the saturated fat or the wheat of that dish, but when your body is stressed it´s getting really sensitive.