Yes, and a fairly substantial one at that. For 5 years, I was a college professor, teaching and performing research in cognitive psychology. For various reasons, I felt my position was not going to work out well in the long run, so I began searching for a similar one at another university. Unfortunately, the market for PhD cognitive psychologists was rather glutted at the time, and my search was proving fruitless. I finally realized that if I was going to have a career, it was not going to be in academic psychology.
After some soul-searching, and with encouragement from my wife, I decided to become a physician. The next couple of years were interesting, as I had to take med-school prerequisites while continuing to teach full-time. I was not accepted into med school the first time I applied--didn't even get an interview. It wasn't until the second go-round that I was accepted.
Irony of ironies: On the day I was accepted to med school, I also received the one-and-only job offer I ever got for another position in cognitive psychology. Not so ironic but even more importantly, my daughter was born the next morning. (Quite a 24 hours.)