I think you need a new keyboard lol. Did you mean ataraxia?
Another word I haven’t heard until now, but yes, I do support this attitude to life. I think I’ve learnt it from my ex. Sometimes bad things happen that are beyond your control and lamenting them is a waste of time, which can be much better spent on trying to figure if there is anything that can be done about the loss or adversity. And if nothing can be done, move on to enjoying other things in life.
I was interested to read that in ancient times, ataraxia was the ideal state for soldiers heading for battle. You can be sure as hell that if I was about to face the prospect of killing others or being killed, ataraxia would be the last mental state I’d be in!
Other than the age difference, what is wrong with her? Is she a mean person? Two_faced? Is she stupid? Lazy? Treat him like he’s a sugar daddy whose only goal is to spoil her? Does she behave like a 16 year old that’s going to grow up to be an awful adult? You didn’t really give any reason for being against this relationship and for thinking less of him other than the age difference, which I’m not sure is a valid reason to think less of either of them if they are happy together.