“Leonardo’s projected treatise on painting was to encompass every subject that would enable an artist to produce works that were “true to nature”. It’s potential scope was huge, and it led him into a whole series of investigations into the appearance of the physical world, including optics, geology, botany, and hydraulics, and most significantly into the principle subject matter of the Renaissance artist, the human body. Soon Leonardo conceived the idea of writing a separate treatise on anatomy; and though this, like the treatise in painting, was never completed, his anatomical studies came to be the most sustained and brilliant of his many scientific researches.
Leonardo’s early anatomical studies were rather unfocused, for he wished to explain every aspect of the human body—not just structural anatomy, but also conception and growth, the expression of the emotions, the nature of senses, and so on.”
I like to believe that it wasn’t so much that Leonardo was “disorganized” as many choose to believe, but that he allowed his insatiable curiosity to guide him in his quest for “truth”. I believe his true goal was to learn truth. So what looks like “going down the rabbit hole” to some, is actually demonstrative of his pure method of following truth. Had he ignored discoveries along the way, it would have been like ignoring revealed truth.