I think it’s as much about effort as it is about expertise (or lack thereof.) With all the time pressures we face, we simply don;t have the luxury of free time or head space to be good at more than one thing.

And that’s fine — I’d rather be great at one thing, good at a couple more, and average at the rest, rather than mediocre across the board. It’s a case of knowing and embracing your strengths, and finding ways around your weaknesses.