It took my boss over 30 minutes on the phone with me to feel she had adequately explained that an email I had drafted was too wordy. Apparently I overexplain things and don't get to the point fast enough.
She then emailed me an example of what she would have written. It was 64 words shorter.
"People don't read past the first two lines of a paragraph!"
To myself: "No, YOU don't read past the first two lines of a paragraph."