Changes in human settings

How fast can a person change its personality? Sounds like reformating your pc and become a diffrent person... 2 and a half months? is it fast enought or reformatting XP is faster my personal record 1 hour? sounds funny? always be alert people around you do they change? do they stab u in the back like an assasin? lol.... omg wat am I talking about....

Well the same old story 2 tell the date of the exam is drawing nearer and nearer yoooorrrrr the creeping fear is shooting up my blood vessels.... haunting u in the night b4 u sleep during sleeping waking up period walau eh....