My mother is insane and it would suck for someone to assume I was destined to be like her. I was never like her, even at my worst, and I’ve only become more sane as I’ve aged.
I think it mostly comes down to two things. You have to share the same values and you have to get along really well. The best way to assess those two things before you marry them is time. Time to see who they are when they aren’t on their best behavior. How they handle crisis, grief, unemployment, disappointment, travel.
I think four years was good for us. It was an eventful four years. We even had a rough time getting along the year of our engagement, and we worked through that. I remember feeling very comfortable and confident on my wedding day because the relationship had already been tested in so many ways I had no doubt about who I was marrying.