Update: Again, I fail to see *why* I get downvoted for this.
Oh, and warn them about the Wasabi. Even if what we get in America isn't real Wasabi, it's still powerful enough to empty your sinus cavity in 15 seconds flat.
While real Wasabi could still sting you like there's no tomorrow, it's actually much much milder than powder ones and the like.... it's actually sweet, and you can definitely tell the difference :)
So the correct statement is "Because what we get in America ins't real Wasabi..." (unfortunately, it's also common for sushi places in Japan to use fake-wasabi ... sigh. )