How do you differentiate between intolerance vs you?

How do you differentiate between intolerance and when you are just being a bad person. An intolerant person will think you are bad no matter what you do or how good you act. However some people will get upset since you did something that was just cruel.

If someone says "You need to die because your gay" that is intolerant. If someone trys to kiss you and you say "Im not gay please dont do that" you simply don't want to be kissed. So how do you tell the difference between someone simply being an intolerant and if its you?

Someone can say you are stupid for liking science but does that give them a right to bully you? vs if you use said science to blow up a school? Now see these are very obvious ones so its easy to tell the difference but what about when the lines are not so clear?

If you have a career and take pride in it and know you are good in it does that make you arrogant or confident in your work? So people would find a reason to bully you because you are confident in your abilities.

However confidence in yourself is a sign of narcissism. So how do you know the difference between if someone is being a jerk and you should stay the same or if you are being a jerk and should try to be nicer? Majority might rule but majority is never ALWAYS right and is probably wrong more often. However how do you know if something you doing is truly bad of if people simply want to bully you?

If someone answers all the the questions in class people might assume they think everyone is an idiot. So they will tell this person off and tell them how vain and self centered they are. Though is being intelligent really a reason to pick on a person for and does answering all the questions necessarily mean they think everyone else in class is a moron or that they know everything? Maybe it just means they enjoy participating in class and are a little over eager but they care.