Hmmm... One of my best friends IRL is an ISTj so I'll just give the advice on 'N'ness that I would give him (if he were to ask for it)
I find that he tends to get
too comfortable with where he is at the time and ignores all ideas of change/growth
He's pretty serious and is known for cutting through and not taking any bs. Not that he doesn't have a great sense of humour, he's just very
cool about it. I would advise him to let go every now and do something unexpected. I look at it from an Ne perspective so the easiest way I can think of is 'adventuring' (a concept all ENTps should hold close to their heart
). Just go out for the day/night without any too many plans and give yourself the opportunity to think on your feet. Its important not to stagnant and to view every minute as a chance to experience something new and better. Better yet, get yourself your very own ENTp and they'll drag you with them, kicking and screaming
Otherwise(if that sounds too taxing
), just get a stack of books on existentialism and consider that its all a big game and nothing is truly real. Whatever floats your boat