I often have a serious face on, especially when I was a kid. I don't make my face do any sort of expression usually so my face just goes like that. I could be having the time of my life and still have that face on. I move my face more often now, but it's like I have to make myself to smile whenever I see someone I know. I usually have my serious face on when I: am feeling emotionless, concentrating hard on someone, am absorbing knowledge, or looking around somewhere fasinating such as a museum (you know, the films, the activity things, exploring around while NOT being rushed, that sort of thing).