4. Every decision doesn't require an in-depth discussion.
Buying a car when you're dating versus buying a car when you're married: When you're dating, you figure out your budget, do your research, and go buy any car you damn well please. You announce this purchase to your significant other by rolling up to their place in your new vehicle and saying, "Hey, check out my new car!"
When you're married, you figure out your budget, do your research, and then have roughly 25 conversations about whose opinion should reign supreme, and do you really need last year's model when the six-year-old model seems just fine? And also, why are we even buying a car in the first place?
Now, apply this to every decision and purchase for the rest of your life. Vacations, holidays, furniture, homes, appliances, parenting ... all of it. Appealing, right?