There's a fine line between an expert and a know-it-all.

The know-it-alls are at the pinnacle of knowledge, not only in their fields, but in a huge variety of others. Hence, they no longer have to receive anything from anyone, anymore.

This may only be happening in their head, but it certainly shows itself in the way they interact with other people.

Experts, on the other hand, may be close to the pinnacle of knowledge in their fields, but they know that they have more to learn, and don't pretend to be experts in fields they are unfamiliar with.

It's easy to slip over, just like when you're colouring a picture and you press on your crayon a little too hard along the edges of the lines.

Fortunately, unlike crayon colouring, it's very possible to come back over the line.