We get used to tolerate, get used to find prob from ourselve whenever there is a prob, get used to think as long as we work hard, the impression will be changed, get used to think the boss is not intentionally to hurt you after all... Once you see a hint that your boss is hostile to you, no second thought, looking for a new place ASAP, and leave before the time he/she can find the excuse to lay you off -or even fire you...