So I watched another tv show about how Leonardo da Vinci was an isolated genius, a towering intellect whose creativity and inventions stump people. How did he do it?
Wrong, wrong and more wrong. Leonardo stood on the shoulders of others. People mention his flying machines. Well, people have always been interested in flight. About 300 years before Leonardo, there was Eilmer, also known as Oliver a monk at Malmesbury who strapped some wing-like gizmo onto his back and jumped off the tower.
He did fly for some yards before crashing and breaking both his legs. He could never walk again but he did fly. Leonardo most probably did know about him.
As for his other inventions and ideas. A good book has been written by Gavin Menzies which claimed that the Chinese treasure ships actually landed in Europe, too, and he notices in his book, that Leonardo's best work is done right after that.
Some of Leonardo's ideas are known to the Chinese who tried them before him. Did Leonardo da Vinci meet the Chinese travelers? Was he enthralled with their ideas, so radically different from what he was used to? Possibly.
I think that history needs to change it's opinion of Leonardo. Genius: yes. Lone inventor who invents all his own ideas: no.
Leonardo was a man of his time and was well read enough to know all about previous inventors and what they achieved. He improved on every idea he came across, found a better way to make it work, but he did not do it all in a vacuum.
He wasn't any more ahead of his time than any of the other 'crazy' inventors back in the Dark, Middle or Renaissance ages.
But go ahead, admire the guy. He was what he was and did a lot. Mostly mechanical toys and objects for his patrons parties. And he cast his giant horse in one go. It's still unknown how he did it.
These days I guess you'd call him the go-to guy and he's still the greatest genius the world has ever known.