I have often been accused of being too snobby and pretentious about whatever new habit I might have picked up (or, rather, become obsessed with). Often, my excitement about something (coffee, new music, whatever theology I happen to affirm that week) leads me to declare myself an expert on the given subject. And, to be fair, this can be a pretty bad characteristic — letting my excitement turn into snobbishness.
Young people often signal through their pretensions what they hope to become: they have discerned, maybe in a limited way, some good and they are pursuing it the best they can, given limited knowledge and experience. They see people whom they admire, or are in some way attracted to, and they try to copy the preferences of those paragons. Such copying can lead to more and more pretension; but in many cases the pretense becomes real: the tastes we aspire to often become our own taste.
So, perhaps, pretension isn’t all bad. At its best, perhaps pretension can help us learn the kind of people we want to become.