Despite spending a bit of time with interns I don't think I'm at all capable of predicting what sort of efficiency and work ethic I might be able to muster come internship. My problem though, is when consultants and senior registrars expect high levels of specialized knowledge and skills from juniors or when they make a big song and dance when someone makes a mistake.
I expect an intern to learn specialised knowledge as they progress through the term. For instance, a Haem intern won't be expected to understand inpatient chemo protocols and what prophylactic meds to chart in their first week, but by the first month in, I'd have far higher expectations of their working knowledge and efficiency in dealing with such patients. Mistakes are understandable, but probably less tolerated when it's from an intern who's failed to evolve.
Absolutely true, though, that some senior doctors and regs alike set unreasonably high standards - but by an large, most don't. Some of those who do ask too much, do so as a way of hoping to "inspire" interns to learn.... surprisingly, some actually thrive in these environments! On the flipside, I also think some interns set their own standards too low, and subsequently under-achieve during their rotations. If an intern's motto is "near enough is good enough", they are likely to be roasted on the wards.