A balanced and skillful approach to life, taking care to avoid extremes, becomes a very important factor in conducting one's everyday existence. It is important in all aspects of life. For instance, in planting a sapling of a plant or a tree, at its very early stage you have to be very skillful and gentle. Too much moisture will destroy it, too much sunlight will destroy it. Too little will also destroy it. So what you need is a very balanced environment where the sapling can have a healthy growth. Or, for a person's physical health, too much or too little of any one thing can have destructive effects. For example, too much protein I think is bad, and too little is bad.
This gentle and skillful approach, taking care to avoid extremes, applies to healthy mental and emotional growth as well.