I don't remember at which point I became so interested in DaVinci. To be honest, artwork wise, I am a much bigger fan of Bottecelli, Titan, Klimt, than DaVinci but I find the DaVinci's application of mathematical (logic) principles to art very interesting. Perhaps, it is because I have always felt so divided between the world of science/math and art. Once I started taking calculus and trig in high school, math ceased to seem to be about formulas and the logical and instead seemed to be more about a certain kind of art. How many variables can come into play and still be covered by a formula? It's just all one big puzzle and is artwork not a puzzle? For one, you rarely have most of the information needed to understand artwork, even if the artist has written a statement saying 'THIS is what my artwork is about...' for there are things that influence art that can not be put into words.
I still remember reading a book about DaVinci in 8th grade. (I can't remember WHY, maybe for a class assignment?) but I quickly became intranced with the idea of writing backwards. My friend Halle & I quickly took up the practice and wrote reams of letters in backwards writing. We became fairly proficient at it and it really peeved our teachers when we had notes taken up... ;)
I also love the fact that he so obviously incorporated the golden mean in his works. The golden mean, which is related to fibonacci numbers which is related to PHI is all about proportion and what constitutes ideal beauty. Did you ever see Donald Duck in Mathematical Land? All of the section about the Parthenon and stars is about the golden rule/mean. Essentially, the golden mean, fibonacci numbers, PHI, it all relates to the proportion and ratio of things. Such as your arm span = your height (which I wonder if is true for everyone?) which is what the illustration of DaVinci's Vitruvian Man (the man inscribed in a circle) is.
Anyhow, Leonardo DaVinci frequently practiced the principles of the golden mean/rule in his artwork (the last supper is one of the famous examples) .
Although the golden mean/rule/fibonacci numbers have been around for a quite a while, they also been taken up by 'intelligent design' theorists. I'm not very familiar with the intelligent design theory, but I think the principles of the golden mean are the crux of the theory...
..and here are some interesting websites about this.
lots o info about the golden mean
Fibonacci in art & architecture
Principles of Davinci
About Leonardo's notebook
...and my class project from a few semesters ago about spiralsabout spirals (yes, a true spiral follows the ratio of the golden mean)