Arkham is intimidating but really not all that complicated at its core. If you want to learn it, what I do is set aside 2 or 3 hours, pull all the stuff out of the box and start to play by myself. I don't really read the rules ahead of time, just a quick skim. Then I constantly have to reference the rules as I go. Within a few rounds you'll have a decent grasp on it, and then you can actually read the rulebook and then play again by yourself.
Personally I can't just read through the rules without context, especially in a game like this.
I'm very much able to read rules and grssp all the stuff around them. My mind has always worked that way, I always end up being the go-to guy for such things.
Guess I'll have to do that soon though.
It it easy enough to teach after?