I can't edit my other comment anymore, but on a more serious note I'd like to debate the claim that the brain has a tree like structure. A tree is by definitio

I can't edit my other comment anymore, but on a more serious note I'd like to debate the claim that the brain has a tree like structure. A tree is by definition acyclic, whereas the brain surely is not. A neuron can even connect from it's axon terminals to its own dendrites. Surely more cycles are present. Hence I oppose the idea of hierarchical note-taking.