Flaubert wrote his famous quote in the mid-19th century, after he’d left his bourgeois law career and was in the Middle East enjoying prostitutes and engaging in orgasmic activity with a 14-year old Maronite boy. He finally contracted syphilis, showing just how much he risked for his subversion. Perhaps the advice, so oft quoted by literati, is really about the writer needing the bourgeois life in order to push against it.