Wow, I am amazed there are couples here that never argue. Mu suspicion is that one or both don't 'care' enough to argue, or that one partner is passive, and the other takes control.
You can have that suspicion, but in our lives it would be wrong. I care tons..and can't imagine my life without my hubby (and I have a couple of friends standing in line for him, if I go first LOL..and I would not want him to be alone, so I hope he takes one of them up on the offer). I've never had any reason to think he feels any differently about me. We really do know each other good enough, and love and respect each other enough, that if we think something we would do would hurt the other, or be something the other wouldn't like..we just don't care to do it.
We've both always had good jobs, and although we never got rich, we also never had to fight about money.
We've been together our entire adult lifes, and there is no one else I'd rather spend time with. We like the same things (spending time with God, being with our family, camping, traveling, sharing our business, TV programs, working with a cat rescue group), finish each others sentences,and think much alike on most issues. Are we tied at the hip? Nope..I'm sending him as a gift to Ireland next week to celebrate his St Patty's Day birthday with our son who lives there. Great father/son time! Will I miss him? Sure, but he loves the history in Ireland, but I've been a few times, and other than seeing my son and his wive, I'd rather stay home and read and get caught up on spring cleaning LOL!
It's just the way it is, and I wouldn't change anything about my life. It's a calm life, it's not at all boring, and yes, it is predictable, and I have no problem with that. 42 happy years..we must be doing something right!