It's the holiday season, although I can't permit myself to have a holiday from my brain. Instead of doing what my heart desires and lounging around hotel rooms in my pants, broadening not my mind but my hips and my knowledge of obscure hydrogenated European corn snacks, I march myself around museums and galleries. It's partly because of cultural curiosity, but mostly because I daren't come home and tell my friends that I spent all my time napping and watching badly dubbed foreign reality TV.

According to Ask Jeeves, I am not alone in my holiday habits. A fifth of all adults (and 41% of Londoners) have tried to impress other people by pretending to be smarter and more culturally aware than they really are. As well as forcing themselves to visit art galleries, some even swapped their trashy beach read for something that looked a bit more cultured – although they did not admit to wrapping a Dostoevsky dust jacket around their Jackie Collins, which is what really clever people do.

Being pretentious, it seems, is the only thing saving us from stupidity. It's fine to say you shouldn't care what other people think of you – that there is a philosophical defence for watching Geordie Shore. But we need cultural stimulation to keep our brains sharp. And if peer pressure is forcing us through the theatre doors and filling our Sky+ boxes with difficult foreign dramas, it can only be a good thing.

I recently visited the David Bowie Is exhibition at the V&A – as a fan. I went of my own accord rather than being pressured into it by a scary clutch of imaginary intelligentsia and was struck by the picture that emerged. Bowie seems to fearlessly embrace high culture, but spent his teens listening to the music and reading the books that he thought he "ought" to like. "I'd convinced myself I was a Charles Mingus fan," was one of the standout quotes from the show. Eventually, he decided to read the Baudelaire he'd bought to stick in his back pocket, and his carefully constructed exterior started to merge with his interior. Sometimes, attempting to impress the people around us is the best way to become the people we want to be. Trying to look smarter than we are can actually make us smarter. And in Bowie's case, his own pretentious leanings ultimately inspired him to create more art.

When you're an adult, no one can force you to keep reading or learning, any more than they can force you to eat your greens or go to bed early. Workplaces are becoming increasingly demanding, and after a day of being challenged and provoked by your job, it's tempting to come home to a night of sitcom repeats and cereal dinners. You might only pick up a book because you can't bear to tell your colleague you spent another night Instagramming your cat – but that book might stretch a muscle or trigger an idea that makes you try something new. Some people are afraid of being found out as philistines, but if that fear motivates us to learn it might give us the confidence to respect and add to the culture around us.