C'mon dude.....anyone, and I mean anyone who doesn't admit they knew the risks of playing football is being disengious.
Nobody knew the long-term effects of concussions. Nobody. The claim, which the NFL chose to settle rather than fight, is that when the NFL did find out a few years ago, the concealed such information from the players.
Again, if you are saying you knew that concussions caused long-term damage with latent effects, you are either a liar or you missed out on a ground-breaking medical publication that would have probably made you a lot of money. If it's the later, I apologize. That sucks, but that's how it goes. Publish or perish.