Yes, I've had people say that to me, more when I was younger, I think, not so much now.
I'd say it was almost always males saying it--in fact I can't really recall any female saying that, but never thought about that before.
I've always found it embarrassing and very annoying! I've never understood those peoples' motivations-do they really think that by pointing out your supposed sadness or misery that this is somehow supposed to cheer you up!?
When I'm thinking about things, I guess my expression must look serious. Plus, I used to be really shy, and maybe they misread my shy nature as being sad, which I usually wasn't-just distracted or deep in thought.
And, what if you have a really good reason for not being smiley and cheerful? I still vividly remember the day my dad died (he was only 55), and I was leaving work to go to the hospital. I remember some stranger saying to me in the elevator, "Cheer up! You look like your dog just died!" I blurted out that "No, it was my dad that just died!", and proceeded to burst into sobs. I had just been barely holding it together, trying to get out of the office building before I broke down, because I still had to drive across town. That's the thing--these strangers can't possibly know what's going on in your life.
I asked my older son this question, as it's something he's mentioned that he hears a lot, and it really bugs him, too. He had a Traumatic Brain Injury a few years ago, and being in social situations, crowds, or trying to have a conversation with someone was really difficult for him for some time, though it's gradually improved.
For him, he said it's always been females. (All except the one homeless guy he used to ride by on his bike, and who now appears to be a female, except for the thick beard that he/she sports!) So, I don't know, perhaps it's a way that some people try to initiate a conversation with a stranger, maybe a lame form of flirting??
Be interesting to see the gender breakdown.
april