Marriage is not something is already built strongly, but its something every couple should learn how to build. Nobody knows what's deep inside every personality not even yourself and most of the time this deep personality will surface on the time you never know and suddenly realized what is this feeling, I didn't have this before, why he's/she's like this, this is not the person i used to know.
That's what personalities is all about, learn how to handle it instead of running away from it.