There are also behaviors that may not come to full bloom until the marriage is underway....
Mild jealousy becomes insane jealousy as the social circle enlarges,
A few drinks when stressed becomes heavy drinking during hard times.
Timid insecurity becomes rabid control freakishness.
etc
Granted, most of the flags are there, but some are folded and in the drawer at the time of marriage.
We live and learn. That might be why I waited 14 years after the divorce before I remarried.