Before you swim for the first time, you'd probably practice certain things on land:
Holding your breath for several minutes; Flapping your feet; Swinging your arms; Keeping your eyes open in a bucket of water; etc.
But everything changes when you drop into that pool.

It becomes difficult to suck in your breath; Your legs fail to respond as they should; Pedaling with your arms is an exercise.
You begin to wonder how people see underwater.
You find out there's a difference between practice and swimming.
And that's how dating and marriage is.

All the experiences you're having in your dating relationship can't prepare you for the actual reality of being married and starting a family.
When he pisses you off, you don't go, "Daniel come and open your door for me; I'm leaving."
This time, you roll to the edge of the bed.

"Marriage is a cult."
This is why you should vet your partners. You should know the things you can tolerate and the ones you can't.
On land, you had the chance to pull your head out of the bucket; Underwater, you either block your lungs or drown.
That's marriage.