This is just a friendly reminder:
It's good for you. Really.
It makes you feel nice, and it's the easiest way to get out of a bad mood. It's pretty contagious, too.
It also can make people around you wonder what you're smiling about, and may quite possibly make you seem mysterious and interesting (even if you're boring and dumb).
Look at Mona. Aren't you dying to know why she's smiling? Maybe she's expecting to get the old heave-ho from Leo or maybe she has gas. Maybe she's an attention whore, loving every minute of this. She looks like she knows a secret that no one's supposed to know. Or, could it be that she's just a happy woman, content with life as it is?
I know, you think I'm looking into it WAY too much, and she's just be posing for a picture, but I don't think a fake smile could possibly be so enigmatic. Her eyes are alive (and a bit creepy). You don't get that kind of expression with a fake smile.
Anyway, forcing yourself to smile can really lift your spirits and change things nicely. It doesn't have to be a fake smile. Just make the conscious effort to find something that makes you smile. Think of someone who makes you laugh, think of something that makes you laugh, and you won't even have to force it.
And remember, laughter is the best medicine.