“If people treat you disrespectfully or speak unkindly about you, remember that they do so from their impression that it is right to do so.” – Epictetus
A lot of emphasis is placed upon first impressions. A large part of this emphasis is there because people make judgments about you very early in their understanding of you. Sometimes people never move past this understanding of you and they may very well continue to judge you. This is not your problem.
If someone decides, based on limited understanding of you, that you are not deserving of their respect there are really only two possibilities. The first is that you have done something to lose their respect. In this case, you should reflect and if the reasoning is sound, adjust your behavior. The second case is that they are choosing to treat you with disrespect based on a misunderstanding of you as a person. In this case, who cares? It’s not your problem. Move on.
If you are in a position where you have to work with someone directly and they treat you disrespectfully or unkindly, respond with kindness and patience. It’s more difficult but still not about you. Maybe they feel threatened, passed over, or like you get more credit than you deserve. Doesn’t matter. It’s about them, don’t make it about you. Keep your side of the table kind, patient, and professional. That’s how the long game is won.
virtus fortis vocat