the overwhelming majority of 24-year-olds aren't very good at making the right decision in those fercbacker for the 49ers is such a man, announcing he's retiring at the age of 24, walking away from a $3 million contract, because he didn't want to trade his health and his life for his loovlihood. joining me now is harry carson to talk about this. it's a pretty remarkable thing to do. >> it is. from when i played years ago, the money is so much bigger now than when i played. but the risks are still the same. you know, there's a physical risk. everybody is aware of the physical risk, knee, shoulder, whatever. those things can be replaced, but when it comes to your brain, it could be replaced. >> we know more now. chris borland said he started thinking about it last season. he had what he thought was an undiagnosed is it concussion, and he talked to brain experts, about the long-term impact on brains, and he just decided the risk wasn't worth it. >> you know what? he's a smart guy. the information is out there now. he has taken advantage of that information, and he has made an informed de