Hmmm!!!! I can remember when I was 13 - 14... when I was 10 foot tall and bulletproof, full of spunk and could piss vinegar over the top of a 10 foot wall. Yup, I was pretty full of it... and myself, particularly when I had achieved something I thought was special.
Some thought I was just an arrogant little upstart who needed a good kick up the arse to 'learn me some manners'.... but there were others (people who understood me (better) and remembered their own youth) who put it down to youthful exuberance. Yes, I was an excitable young man, and sometimes I would get carried away in the euphoria of a moment, so yes, I owe many, many thanks to the kindly, more patient folk... mentors who helped guide me toward better, more respectful and mature ways.
Also, there is a cultural difference here. This young man is Indian while most of us are not, and we are not necessarily going to understand his phrasiology or written/spoken manner, etc, So to say that he is arrogant without understanding his cultural and educational background is probably not the best thing to do. Putting him on the defensive for something he doesn't understand (arrogance in his culture could mean something entirely different) doesn't exactly engender the confidence to present himself or his work more aptly.
I had some Indian neighbours a few years ago, and at first I thought they were arrogant and so far up themselves... until I got to know them better, that is. What I mistook for arrogance was in fact just the difference between us... how and where they were educated/brought up. It turned out that these people were very nice and totally great neighbours... and I thank my mentors for intilling in me some patience and understanding, otherwise I may never have come to know that.
Someting to think about!