Well I think we're boarding on moot, but I love moot things. So it's like saying "learn the basics of neuroscience" to work in any sort of neuro lab. Yeah, technically the "basics" does not mean "all of", but the basics usually mean the breadth of everything, but just not the depth. So I work in a few labs, one being a oxytocin/fMRI lab,. If someone told me to learn the "basics", I would have spent a third of the time learning about action potentials, and a third learning about the PNS...well you get my point: I would have wasted a lot of time going through stuff that would not have helped me directly, despite learning the fundamentals. This lab is very systems level, and not molecular, so the structure of this nonapeptide or 5HT would likely not help me. If I worked my way through their publications first, and asked for relevant papers and meta-studies, I can cut a lot of the crap that is going to bog down a complete neophyte. Of course, wading through papers is going to be laborious, but the "labors" entailed will be going through the textbooks to pick up the relevant basics.
I completely agree that knowing the science is what separates a researcher from a lab rat, but that knowing the science means the papers. The literature is the actual science, before it is processed into textbooks where there is a clear thesis and ready principles and the evidence is already evaluated and ready for digestion. You will need a textbook or two (or wiki), but if youre doing science, the question being investigated won't be in the. The textbooks are a subsidiary, a reference for the literature. Your gains will be a lot quicker if you start off running, even if you trip, than if you take baby steps.
I am certainly less experienced than you as a researcher, but I can probably, by the very virtue of this, relate more to the undergraduate that doesn't know where to start.