What is with people being mean and instantly getting mad

Some girl got mad cus she told me to pick what to offer for her neon swan and I did, and she had the audacity to say “I am not a dumb ass” like no?? I ask u earlier to pick my pets and you said u didn’t know values and got angry when I tried to introduce u to a value websites! WHILE U WERE OFFERING A NEON SWAN FOR MY MEGA DODO EVEN THO I SAID THAT WAY UNDER !!