Yes I think this is an important point, medical culture plays a big role in this. The only place I've seen a similar culture is in the army.

If you're exhausted or in physical pain or have a cold, you not only power through it but you suck it up and refrain from complaining, even if you're assisting a surgery. You may be officially encouraged to know and respect your limits, but if you actually do this you quickly go from being a "brother in arms" to weak and unsuited for the profession.