I gripe _all the time_. It's part of my being. It's just what my family does. I'm Jewish and so I also associate with it culturally. But importantly, it doesn't get us (my family) down. I consider it just observing the world. It's quite stereotypically Jewish to complain and then say "not that I'm complaining." My daughter inherited this lovely (that's sarcasm, another thing that runs in my family) trait from me. My son did not.
I really have to check myself before complaining around other people. And around my wife. Because I recognize that a lot of people, most even, don't want to hear it.
A friend once said about me: "Some people think the glass is half full, others that it's half empty. You just think the water sucks." :-)