Mr. Keyes makes it clear that attitudes — ours and others’ — toward size is what is decisive, and decisively wrong. Discrimination against women, he conjectures, may actually be discrimination on the basis of size. … The Height of Your Life is an odd, breezy book, quick to record a joke, occasionally rueful, that gathers a kind of sadness as it moves along. I haven’t consciously thought about height since I was in high school and realized I would never make 6 feet. … Now I am made to realize how crucial size is in social dynamics, and how cruel those dynamics are. We learn.