Kyler is young, Kyler is immature, Kyler probably is tired of having to fight this uphill battle with his size again and again, but it is what it is, and he needs to buckle down because he's in the home stretch of his ultimate goal of being part of the highest form of football competition
I can maybe get a rough impression of his mindset. Young boy is short and proves himself in Pop Warner football but it's not as hard because the other kids have not grown yet, but still at that age even a little shade is daunting at that impressionable age. Then he goes to high school, proves his worth and feels great but it starts all over again after he thinks winning every game he has played at the highest level of Texas high school football should erase his doubters. Goes to college, bounces around and finally gets his chance having to prove himself again more than others because of his size and wins the Heisman. Now he goes pro, and each step on this ladder becomes more difficult with the level of competition, and it starts all over again
I think he's just tired proving himself because with his size that justification of belonging is doubled, so he is very introvert, and his ego is best friend. He's not a bad guy, but he probably has a lot of baggage he has had to tote around due to his stature
There, and I did not go full blown Mitch with that psychological analysis because I do not state my observations as facts from what I know but how I might feel if I was placed in those big shoes to fill but having little feet lol