I've recently traded a few emails with Nate, host of the WorldBuilding School, and perhaps I might be writing a guest post in the near future.
I've posted about the amazing tutorials of his before, and guess what, here they are again!
Tonight as I flipped through other posts and links I found the 7 Key Skills to Build Your World. Up until reading them I considered myself rather versed in various realms of worldbuilding. Now I kinda question that :)
My degree is a blend of social science and history, and I was no slouch in geography and earth science. But I'm a far cry from knowing all there is to know.
Economy and [physical] science are by far my weakest points. I get the general concepts of cartography, but I don't practice the skill itself nearly as much as I'd like to. I know next to nothing about zoology. I can tell you that predatory animals typically have binocular vision and some form of taking down their prey - fangs, claws, venom, etc. Prey animals usually have their eyes on the side, rather than the front of the head, to provide a wider view of things that could creep up on them. They employ escape measures of escape, like speed or burrowing, or camouflage and mimicry to trick and confuse predators. That's it! I have scraped the bottom of my zoological knowledge.
My point is, polish the things you know you don't know so well. But don't completely ignore the things you think you know because studying them further is still bound to yield surprises.