Explanation:
Know a little about a lot of things because the possibility of you getting to use that many, little knowledge have higher chances of occuring than getting to use the only one skill you're good at, unless of course, you're doing something vocational. And speaking in general health terms, it's also better to be decent at a wide range of fitness, that is agility, endurance, flexibility, strength, etc, than to single one out and be good at it because you can't build power without having both decent strength and speed.
"A jack of all trades is a master of none, but oftentimes better than a master of one."
