A: As with any question there are a number of things to consider. Where are you located? If you are in America people will look at you funny and be inclined to ask if there is something wrong. Anywhere else in the world people will think of you as good company. So, obviously, the answer is that being shy and quiet is only a problem in the USA.
I’m pretty sure that answered your question, but I’m going to continue with some unsolicited advice. What should you do when someone thinks there must be something wrong with you? You can usually diffuse the situation by telling them that you are under a lot of pressure at work and are preoccupied with several projects. This will be considered normal and you should be able to excuse yourself and move away from the nosy loud mouth.
What should you do if forced into a social situation where you are expected to carry on a conversation, or otherwise socialize? If you are female you can simply clutch your lower abdomen and claim “feminine problems.” Other women will sympathize and men just don’t want to think about it. Once you are out of the other people’s sight you can slip out of a convenient side door or window. Men could fall to the ground clutching their chest, but this will probably result in a costly ambulance ride. It is much better to experience a little humiliation. Just lift up on your tip toes with a pained expression on your face. Urgently ask the location of the nearest bathroom and race in that direction until you can duck outside without anyone seeing. If you have time to plan ahead you could bring along something that smells or sounds like you are having digestive problems to help sell the illusion.
What should you do if someone noticed your absence and asks where you were? You need to keep your answer simple. Tell them that things didn’t go so well in the bathroom and that you had to go home to change clothes. You should look like you are in a hurry and tell them that you will give them the details later, but you have a time sensitive project to finish. Then rush off as they tell you that they are glad everything is back to normal.