There was that guy in the 49ers who retired after 1 season a few years back after learning about CTE - I think he’s involved in the research aspect of it. I also think he was a 1st round draft pick and possibly rookie of the year so it was a high profile thing to walk away. Then Luck and now Luke. We are going to see more of this as the players have financial security and can weigh that against the quality of life after football. Gone are the days when guys are having bone marrow drilled out and replaced w a steel rod just to be able to play in the SB. RIP Bob Kuechenberg.