Oddly enough I knew someone a long time ago who had such a high opinion of her own work that she quit a prestigious high-paying job to live on what she could make from writing, printing and selling zines. (I *said* it was a long time ago!) Everybody who knew her told her it wasn't a good idea, but she just wouldn't listen - launched her 'new career' in a blaze of glory - stuck it out for a few months and then had a lot of trouble finding another job because she had a big unexplained gap/failure on her CV. That's literally the kind of stupid decision that could ruin somebody's life - if not forever, then at least for a number of years. There are very few authors, even pro authors, who can actually live on their royalties.