I think it's because I've been there before that it didn't quite work out.

Don't get me wrong. Cedric was just as nice about things as he could be, a really considerate flatmate.

But I went back expecting things to be like they were before, but they're not. I had to change so much to escape from Carrow, that going back felt as if...as if I were trying to go back to fit back into a shoe I'd outgrown.

I wanted to be useful. But I think Ron felt he was getting more out of working with Professor Brutka--Dumbledore--than me. And Mr Snape had others to help him who are much better brewers than me. Like Hermione.