I didn't marry until 41, and didn't have a child until 43. We've only got the one child to love and raise—so we need to protect him from childhood diseases! We need to protect him from all the common dangers of the world: drowning, auto collision, and the like. But we can rest easy knowing he probably will never experience the horror of diphtheria or tetanus. He probably won't ever have to deal with chicken pox, which kept me out of school and caused me multiple days of suffering. And while I had to deal with chickenpox, at least I didn't have to fear polio, which was an ever-present concern in my parent's childhood. I was vaccinated. And my vaccinated parents didn't need to worry about smallpox, which ran rampant at times in my grandparents' childhoods. I live in an era when we can have a single child and have a reasonable expectation that he will live to adulthood and raise a kid or two of his own. That, to me, is magical.