Agree that if your heart isn’t in it, going after a career in medicine would not be very rewarding.
My daughter, who is an MD, and most of her closest friends who went into medicine never wanted to do anything else, and felt it was their calling, so there never was a second choice in their case. They’re in it to try to save lives, and that’s the aspect they talk about most.
Even though most in her particular circle really don’t have to work for various reasons (wealthy spouses, trust funds, other passive income, etc.) none of them would want to do anything else. My other kids feel the same about what they’re doing.
We’ve watched our kids and many others combine their interests with the financial aspect, and a lot of self-motivation, much as your relative has, flu, and it definitely seems to be a winning combination for success.