I've known a few multiple-ejectees but once was enough for me. I was flat on my back in hospital for three weeks followed by a month's sick leave and then on light duties only for two months. The permanent re-arrangement of my spine gives me gyp now that I'm in my 50s. Another fellow on my sqn who banged-out shortly after me was so badly hurt that he never flew again. On the other hand, I knew one or two who were back flying as soon as the BoI had finished with them. It depends on the individual's frame, posture and preparedness.