Does anyone know what terrible memories Dudly had when he faced with dementors?

If I recall correctly, Rowling told in the chat thingy after DH's release, that "he probably saw himself; what he was like" o something along that line - as in that Dudley saw himself, how horrible, utterly spoiled and mean brat he was. I think that makes sense too - Dudley probably didn't have any downright clearly horrible and painful memories but already just the fact that his parents had raised him to become what he was, was subconsciously very painful for him.

A child can not possibly be happy if treated the way Dudley's parent treated him. All in all but for one essential reason that he probably didn't have a single true friend who acrually liked him, because he was such a mean bastard. He was probably awfully lonely inside but didn't consciously see & feel it (or anything that cuased it) so clearly until the Dementor.

Probably a moment where he wasn't eating

He had a flash back of a nightmare he had of Chuck Norris kicking his Arse .