I had a horrible experience at a symposium once, where in the toilet, of all places, I was rudely confronted by the supposed expert on some minor point in my presentation as being wrong. I was so upset it ruined the rest of the day for me, I had an upset stomach and felt like crying, only to get home and check the point...it was on what some law required, and I was right, she was wrong...
This just points out the EGO that floats about in academia...but it needn't always be the case, at this same symposium there was another well respected academic who was very humble and polite and encouraging to newbies like me.