Always be grinding. It’s the modern-day equivalent of the phrase “always be closing,” and in today’s booming gig economy, with many turning to side hustles to supplement their main source of income, it certainly seems to fit. While turning your car into a taxi on nights and weekends or freelancing as a handyman doing odd jobs may seem like a great way to earn extra money, I’m going to let you in on a little secret about side hustles and gigs that most people don’t know.