I love that Heinlein quote. To expand on it with a societal critique, it's not about working in a group; specialisation only works if you have an all-seeing all-powerful brain at the top that runs the entire show. A hive queen. Without a queen, the specialised insects die of starvation.

Some humans would find immense happiness trying to be the queen themselves. Others, to live like a cat. By themselves, with no one to tell them what to do. But our entire modern society is built upon and favours the busy, mindless drone. The education system shapes you like one, and isn't concerned to help you figure out your ideal place in the ecosystem.