Liberal arts majors who become physicians is unusual. They essentially have to get a science BS in addition to their BA, by the time the prerequisites are done, and usually are prouder of the BS than the BA because it represents so much more in the way of effort. I know an MFA who eventually got an MD.
And I know lots of MDs who got their law degrees later. It was a piece of cake to get a law degree after med school. What I have never met is someone who got an MD after a law degree, proving to me that lawyers are, by and large, really dumb.
Now, I didn't say I knew absolutely that CK didn't take much in the way of hard science prerequisites. But I do know of well-placed people getting into med school without prerequisites.
He went to Oxford for three years on an academic scholarship. Pulitzer Prize winner. Not someone who needed extra pull to get into Harvard Med. Did some pioneering work in psychiatry.
And he did indeed start out in hard sciences, switching to liberal arts later out of interest, not lack of accomplishment.
I’m not really a K fan, but his brains and accomplishments can’t be denied.