If I've learned anything from my extended family, it's that you should not let your adult son live in your house rent-free for years with no job and no prospects. When I was a kid, teenager, and college student, one of my biggest fears was that I would never be able to get a job, and I would be living at my parent's house and mooching off of them for my entire young adult life. Luckily, that hasn't happened yet, but the fear of such an existence still lives deep within me, and I will never allow it to manifest into reality.
One of the things my parents did to help set me up for success was not kicking me out of their house the moment I turned 18. Because I wasn't worried about rent before I left for college, I was able to thrive in college and focus on my education. One 18-year-old on Reddit isn't so lucky; his dad is making him move out or pay up to prevent him from becoming his brothers, who were living with their dad until they were 22 and 23, respectively.