I had a friend who seemed to look down on me because i was into "geeky" things. And another thought i listened to "boys music"
Nothing wrong with not fitting into the crowd. Be true to yourself.
Your bro has a high opinion of himself albeit he does sound insecure which should offer some consolation or show a chink in his armour
But yeah sometimes i wish i had a little bit of such n suchs confidence but i don't want to be them per se