Does anyone else's 13yo actually listen when you talk about online predators?

So I had the Talk with my 13yo about not sharing personal info, never meeting online friends in person without a parent, etc. He listened politely but I could tell he thought I was being paranoid. Then like two weeks later I was checking his account (I'm not sorry about this) and saw someone 20+ years old who'd been DMing him trying to get him to play games "without parents knowing." I showed him the messages and THEN he took it seriously. I'm glad I caught it but also... how do you make them understand this is real BEFORE something sketchy happens? He's not stupid, he just thought it couldn't happen to him. How'd you guys handle this?