Why do some people can insult others and don't feel that they are insulting but they themselves are quick to accuse the other person of being rude if the same situation happens. The second person then says that he is also insulting and without realizing it. To that the first person says something like 'wait a minute are you arguing here with me now and going in cycles?'.
Why it is sometimes like that?

Some people have high standards/expectations from others and are opinionated/judgmental (this doesn't make them bad people - just very direct ones), they also get disappointed and feel alone frequently. These people seem that they don't like their own medicine either... sensitive, quick witted and a lack of effective communication on their part... maybe immaturity when it comes to people relations and a bit self centered. In actuality they are very emotionally sensitive people and are bothered/angered very easily... the need to be correct and have their opinions valued is necessary in their relations and them as intellectuals. Need to be reassured and feel important... or have their feelings/thoughts validated. Also known as the ENTJ personality type!

Quick to pass judgment but don't like to be judged... what is this persons relationship with their parents like? "Usually" it is a learned behavior. Chances are they are controlling, organized and have no issues telling people what to do or where to go with any situation or position. They exhibit these behaviors to hide their true self... this is why I don't look at them as awful people but people who lack effective communication with other people.

Have you tried confronting this person and telling them how you feel? Even though it might upset them; they need to know if something is wrong and effecting your relationship with this other person. It will take a gentle approach and keen listening. Is this person upsetting you? You shouldn't tolerate insults from anyone.

Have you tried confronting this person and telling them how you feel? Even though it might upset them; they need to know if something is wrong and effecting your relationship with this other person. It will take a gentle approach and keen listening. Is this person upsetting you? You shouldn't tolerate insults from anyone.

Yes that I told that this person that I feel being judged and she/he was sort of 'what are you talking about, who is offending you?'- it felt as if this person wanted me to: feel stupid and take my words back and even though I feel bad I am not supposed to say to this person about that because he/ she is always right (someone gave me an advice and at the same time judgments offended me, I was quite shocked to receive that at all as this site I imagine everyone should be friendly and try not to judge anyone. When I tried to say that to that person I received surprises and more judgments.)
Thanks to you, it's always nice to know that everyone is entitled to a non- judgmental support!