For anyone unaware, this joke references a conflation of the Spock we all know and love with Dr. Benjamin Spock, who wrote some of the most prominent books on child rearing. https://en.m.wikipedia.org/wiki/Benjamin_Spock
I was (probably at some point willfully) unaware of this most of my childhood, and it was more fun to think about than the real thing. I miss the days when I could make up my own answers to references.
:p