The detail that works beautifully alone may not belong in the whole.

Work sometimes contains a piece that is genuinely excellent and still wrong for it: the elegant paragraph, the clever feature, the joke that stops everything for a second. Its quality is what makes it hard to remove, because you judge it on its own terms instead of by what it does to everything around it. Fit is a separate question from quality. A thing assembled from best parts is often worse than one that simply agrees with itself.

When you cannot tell, take the piece out and read what is left. If nothing is missing, keep it in a file for something else.