I had an attending who was well and truly stupefied that we didn't already have Robbins essentially memorized by the time we started residency. For a while I thought he was joking just to put a little light-hearted pressure on us, but it didn't take long to realize he was stupefied anytime we didn't already know ANY given thing if it was in text anywhere in the world, though he was somewhat more forgiving when it came to the art side of the job (pattern recognition, etc.). Later in residency I found an attending who pulled out Robbins on a somewhat regular basis to look certain things up, and I finally stopped feeling so bad about not having it memorized. By the end of residency I was reviewing Robbins yet again for board preparation.
If only I had memorized it during medical school I wouldn't have needed that dang residency anyway....
I also had at least two different senior residents who were exceptional, one in part because of being very driven and having already been a physician in another field for many years, and the other because of having been a practicing pathologist overseas for years but his credentials weren't recognized so he had to start over at residency. Both were sometimes awesome resources, but both also had a knack of overtalking everyone else at the scope, spurting out diagnoses before anyone else had a chance to see what tissue we were looking at, and arguing with faculty about why something was or wasn't X. One had a tendency to actually quote page numbers from the WHO books or other reference texts, and was WELL known for sighing dramatically and saying "bah, if you would simply read the book, you would know, it is OBVIOUS..", and teaching by doing everything for you then pointing and going "SEE? Like THAT," and offering a politely paternal "gah, what a *****" look. More frustratingly, they were almost always "correct," if not ideal in their methods, even in academic arguments with faculty.
Point is, yes -- almost certainly you'll run into some attendings &/or other residents who will contribute to your feeling of drowning in a sea of your own ignorance. But that too shall pass, and eventually you'll be able to respectfully mock them on the internet.
I mean, page numbers. Really? REALLY??