< The forgotten path of polymathy
Working knowledge is a solid criterion, for sure. I think another good measurement for "deep enough" is to compare where you began with where you presently are. Do you have the same feelings toward what you're studying as you started with? Then you can hardly have studied it to any meaningful depth. Have your feelings changed? Do you regard your subject, and thus the world, with a markedly changed perspective? This is a good sign of having learned something. A certainty of learning is that everything changes.
I think I must be holistic, if only to the extent that I'm a bounded receptacle of energies. Perception, registration, adjustment—education is only so many alterations of such kinds as these to the internal activity. All this I take for consciousness is just the crest of an already receding wave. But even if the node is meaningless without the network, we can still speak of it individually, and the pattern is at least partly present in the node, too. I mean that I'm a synapse, I have a role to play. I can do so in depth, or not, as I prefer.