The two top-voted answer includes WAAAAAY more information than the XKCD comic, so they're not really comparable. The third one explains it pretty simply.

That's exactly the point: some experts, when asked for a simple explanation, produce a huge info-dump in simplified terminology, and most experts thought that an appropriate response (see upvotes) - failing to realize that the result is anything but simple.

It takes a special skill to eliminate all the non-essential information and produce something truly simple to understand, like the comic.

Myself included. So many interesting topics to touch on when explaining something.

The only reason I ever manage to be short in text form is being able to go back and delete.

Oh, gotcha, agreed!