Here's an important piece of advice for you today. When you see someone, whether it be in the office, on the street or in a bar, and they look sad or unhappy or, in your uninformed opinion, too serious, do not say to them:
"Stop looking so serious!"
"Oh, it can't be that bad!"
Number one, yes, it can be that bad.
Number two, you have no idea why the person looks serious so, I repeat number one, yes, it can be that bad.
Number three, if the person felt like smiling, chances are, she'd be smiling already, you twit-wad.
It is okay to ask, "Are you okay?" If the answer is "Yes," take her word for it and walk away you ignorant dip-shit. If the answer is "No," you may then ask:
"Can I help?"
"Is it something I said (did, wrote, etc.)?"
Now, if the answer to either of the above is "NO!!", even though you know the answer is "Yes," just walk away. Dare I say, walk away quickly. If the person wants you to know why she is serious, not smiling and whether or not it is, in fact, "that bad," she will eventually get around to telling you, she will get over it or it was none of your business in the first place.
Now, if you'll excuse me, I have to walk up the hall and bitch-slap a co-worker.