For example, you might not be in crazy love with your current boyfriend/girlfriend but you decided to marry because you thought you were getting old, you thought this is your last chance, etc or just because they were great enough people to marry and live forever with.
Maybe you wouldn’t have chosen him or her if you had been younger.
Maybe you married because he/she chased you so much and so long and you were impressed..
The list can go on forever.. I hope you get the point!