Do you want a surgeon operating on your brain that has never changed his child’s diaper? Or couldn’t make a home-cooked meal? Or perform simple first-aid on someone until an ambulance arrived?
I specialize in the sciences (engineering to be specific) but that doesn’t mean I can forgo other things. For example, I’m a licensed private and glider pilot and glider instructor. I enjoy cooking, construction (and demolition). The point of the quote is that some people get so focused into what they do that they forget the other things and could be useless unless in a specific situation.
I’d rather be operated on by someone who is an expert at brain surgery who may not be able to do these things than someone who can do these things but is not an expert at brain surgery.
My point was that Heinlien’s quote is typical of many maxims and epithets. They sound good at first, but when you analyze them, they usually don’t make complete sense.
I’m glad you’ve made so many accomplishments. I agree with you that we ought to study and excel at all those things we love to do. But we also have to admit that some people are better than others at certain things. Relatively, like it or not, they are experts or specialists, and they are the ones we depend upon in critical situations.
Same here - only, I have never flown a glider. I find that when things get that quiet, I break out in sweat, for some reason...