Like from the time you met. Things that made them the perfect match initially that have changed. Any non negotiables? Music tastes? Lifestyle changes?
Edit: so many of you thinking I'm saying change in music tastes is a reason to leave someone.. Not my Intention.. Just a trivial thing as an example of other trivial things you may come across.and it's not about leaving someone or divorcing but more about what might bother you enough to say something