Thinking about it, and this is just a possibility and potential headcanon, what if his fear of failure, love of mane styling and over confident persona all stem from Rainbow Dash rejecting him when he was young?
Her rejection hurt him and he gained a fear of failure.
Her colorful mane made him interested in mane styling. It’s also an excuse to try and get closer to her.
His personality is a defense mechanism because he never properly processed his feelings over the rejection.
Maybe I’m just reaching here, though.