judging words

Sometimes words don't mean what you think they do, but when you learn their real meaning, sometimes it doesn't matter. In a way, they'll always have the meaning (or be attached to the meaning) that you originally assumed. Does this cause words to change meaning over time?

With words as is with humans. We often make incorrect judgments about people only to realize our mistake after time. However, do we hold on to these judgments the way we hold on to word meanings? And wouldn't it be unfortunate for someone to change over time to match an incorrect judgment made of them, unless of course the judgment was a positive one?