People aren’t mean in a vacuum. There is always a reason why. Sometimes, compassionately identifying the reason for the person’s behavior towards you may be helpful in coping with the situation.
First, the person may be fundamentally unhappy and by making others feel small, that person may have momentary feelings of superiority and importance.
Second, depending on the professional setting in which you must interact with this person, they may have been treated the same rude way when they were in your shoes and believe that it is helpful to you or that you should experience rude behavior because they had to experience it.
Finally, you may personally activate negativity in that person. What I mean by that is, by being successful, competent and respected, you may be a mirror to that person’s inadequacy and insecurities.
Obviously, none of these is an excuse for someone to be rude to you. However, by identifying the underlying reasons for the person’s behavior towards you, you can remind yourself that the person’s behavior has nothing to do with you and has everything to do with that person’s subconscious triggers. This realization may also help you make peace with the situation and not take it as personally.