Be (like) water off a duck's back: if criticism is water off a duck's back to someone, it has no effect on them at all. He's always being told he's lazy and incompetent, but it's just water off a duck's back to him. (source).
According to the "Big Site of Amazing Facts" this happens because oil and water don't mix. When a duck is swimming or out in the rain, the bird secretes an oil from glands near its tail. With its bill, the duck rubs the oil over its body. The oil keeps the water from soaking through the duck's feathers, making the bird "waterproof."
President Benito Juárez had to overcome many obstacles but at the end was able to defeat the hurdles. Many towns in Mexico erected statues of Juárez in his honor. Juárez proved he was not affected by the "elements" and these sculptures are not affected by the elements, no smog, no rain, and no wind! Thus the wind does nothing to Juárez. (I know the essence is lost in translation, so I leave my original explanation in Spanish below).
Ente los individuos, como entre las naciones, el respeto al derecho ajeno es la paz. Benito Juárez
Among individuals, as among nations, respect for the rights of others is peace.