It absolutely dictates my mood. If the house is trashed, I'm a total UA Violation.
If it's clean, I'm in a zen-like state. Calm as a cucumber. Happy as a clam. DH is starting to learn this. So are the kids. At age 2 and 4, they banded together and cleaned their room, completely spotless, as a surprise for me. They wouldn't let me into the room until they were done. Cuties.
It's the inefficiency of a messy house that infuriates me. There's nothing that I hate worse than walking through the house and knocking stuff off tables and chairs and benches and counters as I pass by just because there's too much stuff piled there! I need an open hallway, because if I trip or stumble, it just drives me mad.
My bedroom was completely horrible until yesterday. The grumpiness is linked directly to the useability of a space. Walking into my room, I'd trip on clothes, a laundry basket, a stack of christmas gifts, just random crap....it made my blood boil. So I took an hour last night and cleaned. I still have to work on my sewing area, so it's useable, but other than that the room is a happy place.
And if the entire house is trashed, the best thing for my soul is to choose one room to clean, make it my oasis, and keep walking back and visiting it to calm down and get encouraged to tackle the rest of the house.