Marriage DOES NOT HAVE TO BE Like That

All my life I've heard various sayings about marriage. But I hate these the most:

You'll never really know the bad sides of your partner until you marry him/her.
It's normal for newlyweds to have disagreements a lot. For instance, the case of toilet seat... she wants it down, he wants it up.

It's similar to the case of chickens and eggs (which came into being first?). My only question is that, why? Is it a common practice to play it cool, pretending into a flawless being in front of your would-be spouse? And when you do get married, you don't have anything better to do than arguing about toilet seats and similar topics? (like, why can't men find things in the fridge even though they're right in front of their eyes... why women don't have keen sense of direction, etc.) They're silly anyway. In case of toilet seat, it's easy. Whoever wants to use it, just adjust it to her or his own need. And you, women, instead of scolding your husbands, wouldn't it be much simpler if you help him finding things on the fridge? And you, men, can help women in the case of finding direction (by reading a map and then asking for help if need be). I believe it's not always like that, though. They are men who are very observant and meticulous that can find the tiniest piece of cheese on the fridge. Or women whose sense of direction is excellent.

However, I can tell, many people nod fondly, agreeing to the sayings. Why? Is it because they believe in the sayings? Or maybe because they experience a similar condition, then imbued by the conditioning, they vehemently agree?

Isn't it just a matter of choice? My partner and I chose not to heed the sayings. Other people may create their own sayings and beliefs.

We choose to create our own.