Next layover you have with this jack@$$, take him to the hotel bar, buy him a few beers. Put yourself in the following mindset before you open your mouth:
You must not be arrogant towards him as, like it or not, he has vastly more experience than you in aviation. You must approach him in this way as an equal HUMAN, not an equal pilot (even if your skill level is in fact higher than his, which it may be for all I know). This is how you avoid a holier-than-thou attitude of excessive assertiveness, which is not much better than HIS attitude is towards you. This may create a space in which he will actually LISTEN to you. When he is all liquored-up and happy, in as friendly of a manner and wording as possible (your own words, of course, more gentle than these) persuade him to:
"Get over yourself. Try to enjoy your life and your job more. You are not better than everyone else. Neither am I or anyone else. And no one would care if you were, either. Never stop studying hard, fly as well as you can, and do your job to the best of your ability. Try to expand your own box a little when you can, WITHOUT looking down on everyone else because they aren't as "perfect" as you".
For yourself, remember these things for the balance of your career:
If you are a captain, give your FO's enough space and autonomy to do their job well, and trust (but verify!) them to get it done. Watch what they do when you let them do their job their own way; you just may learn something new. If you don't like it or they aren't up to snuff, take command and change it. But don't pull that trigger over stupid little micromanaging BS things.
If you are a first officer, give the captain enough space and authority to run the ship his own way without constantly second-guessing him on stuff that is more to do with his personal rhythm than flight safety. If it is within the bounds of legality, safety, "standard-enoughness", respect, and reason, learn and try the captain's way of doing things, even if you don't like it, just to exercise your own mental flexibility. Remembering that, it his ship to run as he prefers to run it. With the exception of the aforementioned points, it is not your place to make him flow with your rhythm, but it IS your place to "be the chameleon" and flow with his. Of the things you learn while doing this, use your judgment to keep what works and chuck the rest. That includes everything I've just written here.
Have a beer. Lighten up.
