There's a good reason why Doug is my best friend, though I tend to forget at times. ("Why the hell are you making so much noise with that chip bag? And do you have to use so many words when you talk?")
Date nights (and days - praise God for children who are old enough to be at someone else's house for 24 hours!) allow us to have uninterrupted conversations, so that we can remember these things. And even when we do disagree, it's much easier to be grown-up about it when we're alone and not exhausted!
Here's an example of an actual conversation that Doug and I had while the kids were gone this weekend...
Me: [from upstairs] "FYI - I have boobies up here!"
Doug: [from downstairs] "Boobiiiiiiieeeesssss!!!!!"
. . . what?
Okay, so not ALL of our conversations are deep and meaningful.