I don’t know the oldest in my program but it was older than I am. I started neurosurgery residency at age 35 completing at age 42. All of the old-timers completed residency. Others did not, either quitting, getting kicked out, or unfortunately even suicide. I am glad I got to spend my 20’s in a more carefree lifestyle rather than within rigors of medical school and residency. While I am 50 now I still love what I do and could not have asked for a better career path. While I wouldn’t want to at this point, even at 50, I feel that I could handle being back in residency…if they paid more. Although I don’t know when I would retire, neurosurgery is lucrative enough and I have been frugal enough to know that I could do so at anytime (and frugal being a relative term as I own multiple vacation homes, exotic cars, go on luxury vacations, etc).