One of the effects of civilization is to diminish the rigour of the application of the law of natural selection. It preserves weakly lives that would have perished in barbarous lands.
My tides were fluctuating, too - back and forth, back and forth - sometimes so fast they seemed to be spinning. They call this 'rapid cycling. ' It's a marvel that a person can appear to be standing still when the mood tides are sloshing back and forth, sometimes sweeping in both directions at once. They call that a 'mixed state. '