How much can you change your personality?

some people might not really believe what i say now.i seriously think that it is quite impossible to change the personality which make us unique maybe...cuz it is hard to change the way we view things based on our experience,our background...and what we can do is change our decisions,but sometimes when your feeling make a decision seem better than the other u might choose that..so personality does influence our decisions,unless we feel okay to do whatever thing we need to decide...but we just need to resist what our feeling tell us to do sometimes and let the rational mind to take over.and to me,it seems quite hard,girls are always you know emotional,which many guys just wouldn't understand..........and suprising i find my childhood values do affect my judgement until today.