Sometimes it's hard to believe how different people perceive things.

I'll never forget the last time I visited the Dell website, it had some popup dialogue constantly jump into view on the side and then disappear again after two seconds or so. It was so infuriatingly distracting to me, meanwhile someone else sitting next to me didn't even notice it before I pointed it out. Which I guess explains why that same person often has trouble finding a seemingly obvious button on screen - it could jump across the screen and some might still not see it.