I occasionally walk around smiling in work-type contexts. I can’t help it; sometimes the things I’m thinking are so pleasing. A sadness is that I probably frown the most at home, where I have to track and remember things without the systems I have in place at work, e.g. went to the grocery store Friday and forgot salt and dishwasher soap, then had to crush fancy salt to make chocolate chip cookies yesterday. Can’t run dishwasher, etc.
I would much rather home be the place I wander around thinking happy thoughts, and I would definitely like my face to reflect my adoration of home and the people in it, but alas.