After all, if someone you know is planning to quit her job and move to Alaska because her horoscope told her that Tauruses need more spontaneity, you shouldn't tell her to stay because she's actually an Aries. You tell her to stay because astrology is provably bogus.

Maybe you should, if you're in a hurry or she's likely to stop listening to you entirely should you assault astrology too directly... (and if she's actually an Aries).