Yep it's funny, and it might have, I just know that it hissed at it. :P
That reminds me of another time, it was either the same cat or Bean when he was a kitten, and my mom had put a block of ice in their water bowl since it was during the summer. Well, he had never seen ice before, so he smacked at it a bit, hissed, then ran away. lol :P
Yeah I've seen people do that same thing with sliding glass doors, lol.