This year marks the twenty-first year since I received my medical doctorate. Since then, I have not for one day regretted my undergraduate major in English and American Literature. As the years have gone by, my knowledge of literature has given me a resource to hedge against the way medicine is practiced today — that is, data-driven dehumanization. A humanities degree offers me perspective, the ability to empathize with the plight of the ill, and most of all the ability to communicate the concepts of science in a way patients and other professionals can understand.
To any student who wants to major in the humanities, I say go for it. (Or if you already went for it, congratulations.) The world of technical knowledge will always be there for you. You may be a bit behind your more technically trained colleagues when you start your post-graduate career (I was), but while you can close that gap, most of your colleagues will never make up for the loss of wisdom and human understanding, of empathy for others, of the ability to discern the truth, and thus of the ability to sniff out a lie and render it harmless.
Knowledge of life and culture is knowledge, too. It doesn't fill the wallet directly, at least not at first, but over the years those who truly study and learn the humanities discover that others who lack that grounding often ask for advice, and usually respect the wisdom given. Insight and clarity of thinking is like being physically strong. It is something you can achieve when you are young, and if you care for it properly it can be with you always, but if you don't acquire it young you will find it much harder to learn when you are older. It is knowledge that lasts.
Practical knowledge, on the other hand, has the shelf-life of raw salmon.
ONE FINAL NOTE: Everyone thinks to get accepted to medical school that you have to major in biology or chemsitry. I have heard this one, and heard it, and heard it, and heard it. Every guidance counselor I have ever talked to will tell you the truth, that you can major in anything you want to and still go to medical school. Counselors and medical schools try, but nobody listens -- it is like the myth that cold weather gives you pneumonia; there is not an ounce of truth to it, never has been, but the belief cannot be stamped out.
But I tell you, as someone who majored in English and went to medical school -- medical schools don't care what you major in! And majoring in the humanities does not hinder your medical education. I swear it's true, and I am living proof.