I think too many people a) misunderstand the terms introvert and extrovert and b) fail to realize that when a test labels them as one or the other, it only means which of the two poles on the spectrum they are nearest.

In common usage, the terms have morphed into synonyms for shy (introvert) or outgoing (extrovert) but the terms have more to do with what types of settings feed or drain our energy.

I happen to be a not shy introvert.