And it is exactly how a person married 5, 10, 15, 20, or 50 years should feel, too. Sure, you probably won't think it's cute anymore when you've spent fifty years reminding your spouse to set the alarm or picking up their socks, but by then, you should have a much deeper connection that won't even be touched by something so superficial. My definition didn't just come from being a newlywed. It's come from an (albeit short) lifetime of observing couples who have been married a long time and who have been through enough crap to have experienced that "do or divorce" moment at least once.
I agree, partly. There is a difference between a happy marriage and a successful one, though admittedly, a very fine one. However, the "happy marriages" that end up in divorce court after a few years of delirious happiness are still failed marriages, and the marriages where the moments of happiness are few and far between but where the couple chooses to struggle together anyway all the way to the end are still successful ones.