In the first case, Boss had to translate your "Can I take Friday off?" into "Can I do without this employee Friday?" That's an extra thought process. (And you know how some bosses hate to think!) However, in the second case, "Boss, can you do without me Friday," you did Boss's thinking for her. Your new wording made managing without you a matter of pride for Boss. "Of course," she said to herself. "I can manage without your help Friday."
