“The grass is always greener on the other side of the fence.” The lesson implicit in this aphorism, that we should be satisfied with what we have, discounts the possibilities that you are standing in quite a barren patch indeed, or that the other grass IS greener, or perhaps that a life represented by greener pastures is not just our desire but a necessity.
But human beings have a problem with sorting out desires and necessities. It is always worthwhile, for instance, to pray for discernment so that we might ask God for what we need, not what we want. Spiritual maturity is when we know He will answer along those lines anyway: but we must keep our priorities straight. We should look less to the pastures over the fence and over the horizon, and more to the One who nurtures those pastures.
Our culture (what the Book of Common Prayer calls “the world, the flesh, and the devil”) continually distorts this understanding. The tendencies of our natures to be dissatisfied with what we have, combined with the spirit of the age that tells us that human devices ultimately will be sufficient to satisfy every human yearning, add up to an upside-down world. Upside-down values, upside-down actions, upside-down results.