I don't care if it's a sad good-by or a bad goodby, but when I leave a place I like to know I'm leaving it. If you don't, you feel even worse.
Another example of foreshadowing. Holden would like for there to be clear signals that he is now leaving a certain place, even if he is leaving it begrudgingly. Being expected to leave a place, either physical or emotional, is that much worse when one isn’t given a goodbye, an assurance of the past.
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