In book II of "On the Nature of Things," Lucretius points out that atoms are lopsided. He says that this is obvious from the way in which they are observed (where observable) to move. If they were perfectly and symmetrically balanced, they would fall straight away to their destination -the Earth- like rain drops, and would never bump into each other. Instead, however, the reality is a random, chaotic, Brownian motion in which atoms zig-zag, bounce off one another, cluster, and dissociate frequently, repeatedly, and eternally.
Human beings are lopsided too. Our hearts are to the left, our livers to the right, our spleens to the left. And our life's course is anything but straight. Perhaps nature made us this way, like the it made the atom, like it made the solar system, to cause us to bounce around --getting involved with some other groups of atoms (humans), disassociating with others, constantly and continually. If we could zoom out, and watch the course our lives take in 1 minute, I bet it would look much like the motion of an atom.
So,if it is our nature to bounce around, explore, and experience (which I believe it is), why do we feel anxiety when we feel the need to change course? Does the atom feel scared to bounce into another?
It is because society, trying to force us to make our lives straight for its own good, has succeeded in convincing us that it SHOULD be straight. And when our nature tells us to zig-zag, our minds fight it. This is anxiety.
We are lopsided. We're not supposed to go straight. Nature didn't build us that way... because she doesn't want us that way. She wants us like the rest of her designs: moving, seeking, bouncing, creating alliances, dissolving them, growing, decaying.
Ideals --and societal ideals in particular-- are straight trajectories. How do you get lopsided, wobbly things to follow a straight line? You keep them ignorant of their true nature; you convince them that they AUGHT be straight, you incentivize the "right" path, and you punish deviants, so that when they have an urge to deviate, their training and experience keeps them in line.