At one time some of them were used so much that they became trite, we suppose.
Maybe that's why we don't hear many of these quite as much anymore. But they still stick out in our memory and maybe you still hear a few now and then.
Anyway, here they are -- along with their explanations:
Irrational. Out-of-balance. Nuts. I tried to reason with her but it's hopeless. She's crazy as a loon.