The answer is that many ML solutions are leaky abstractions. See: https://medium.com/@karpathy/yes-you-should-understand-backprop-e2f06eab496b#.3dtcufc82 https:

The answer is that many ML solutions are leaky abstractions. See: https://medium.com/@karpathy/yes-you-should-understand-backprop-e2f06eab496b#.3dtcufc82 https://medium.com/@karpathy/yes-you-should-understand-backp...