I was surprised to learn this one, given that I always presumed Julia Roberts would be kind of down to earth in real life, given the kinds of characters she's played (yes, it was her turn as a prostitute in Pretty Woman). And yet, looking back across the span of her career, I was shocked to see that she's got a reputation as a diva.
To the point in which even the likes of lovely old Steven Spielberg reached breaking point: whilst filming Hook, the cast and crew apparently nicknamed her "Tinkerhell" and the director cut down her part greatly as a result. To be fair, she'd apparently gone a bit insane at the time, having recently split from her boyfriend, but c'mon, you're in a Spielberg movie, Julia - don't annoy one of the most influential men in Hollywood!
Relationship issues or not, though, that wasn't a one-off occurrence: Roberts has also been called out for her inability to work with other woman (Cameron Diaz, to name one example). Apparently it's a pretty well-known fact that she's difficult to work with, anyway, so I've apparently been living in some sort of dream world where she's a friendly prostitute with a heart of gold. A man can dream.