I'm in no way even close to being in the medical field, but I could see it as an unreconcilable dichotomy between the hippocratic oath and the fact you're going to be causing damage no matter what.
Sure, the hemmhorage needs to be fixed, so you're preventing further damage, but every cut may cause unknown ramifications. Anyway, I'm postulating a neurosurgeon would be aware of this, and have to carry that around with them.
Medicine as a career offers immense personal fulfillment, variety, human interaction, and prestige at the expense of dealing with difficult outcomes and ranges of personal sacrifice -- neurosurgery as a specialty just takes all of these to their extremes.
I value the former and find ways to discount the latter. So I am very happy. Though sane or not would be up to others.
Though some people are less burdened by golden handcuffs and sunk-cost fallacy
Plus, I've never met a happy (or sane) neurosurgeon