2 hours after he left an Anesthesiologist I didn’t know came to check some PCAs, so me being me, started asking questions about the device and given that I’m thinking about studying medicine I asked about it and he told me where he studied, what he did afterwards, started showing me the documentation anesthesiologists use.

Are you being considerate of the doctors’ time and attention? They have work to be doing. As in this example, he came in to check PCAs. Sometimes people can even volunteer information (like showing you the documentation anesthesiologists use), but maybe because they feel socially compelled in that moment to do so even when they should be on task.

Another possibility - maybe your boss is trying to maintain cohesion between nurses. You seem to have a fairly low opinion of the other nurses. Separating yourself and trying to speak only with the doctors kinda demonstrates an intentional division with new co workers that is liable to lead to larger problems working together down the line. Maybe he expects you not to respect their judgment calls, or to put doctors in a tough position by saying, “doctor x told me we do things THIS way” when that process is all-but-on-paper owned by nurses.

I know you’re viewing your situation as learning, trying to get smarter, intentional curiosity - but I don’t really think that’s the problem your boss has. Maybe if you accomplished this in a different way, he wouldn’t complain. Your boss definitely doesn’t want you to be dumb.