"They were careless people....They smashed up things and creatures and then retreated back into their money...and let other people clean up their messes."

Nick was talking about Daisy and Tom Buchanan when he said this in chapter nine, page 179. This was towards the end of the book, after Gatsby died and Tom and Daisy went away and came back to the state. Nick saw Tom outside a jewelry store and they shook hands. Nick says this right after he is thinking about how he could never forgive or like Tom. His justification for not liking or forgiving him is that they were careless. The quote says that "They smashed up things and creatures..." This part of the quote could be saying that rich people or those with a lot of money cause havoc. They ruin fun of things and act too proper. The rest of the quote "...And then retreated back into their money...and let other people clean up their messes." You could take this literally and say that they were rich and when they were done causing their havoc, they went right back to all of their things they bought with their riches and let the maids clean up after them. It shows how materialistic Tom and Daisy were. Other people in this book were mentioned as being materialistic, also.