Higgs Boson, part 3

The physicist John Wheeler once proposed a challenge: How can you best explain quantum mechanics in five words or fewer? ... When I posed the question about quantum mechanics, the best answer was given by Aatish Bhatia: "Don't look: waves. Look: particles." That's quantum mechanics in a nutshell.

 ~ Sean Carroll, The Particle at the End of the Universe, p. 33

I love the juxtaposition of the above image: a child reading Introduction to Quantum Mechanics as though it's a bedtime story. Children are often so much more capable of comprehending the Universe than the adults around them! To a child, Quantum Mechanics may well sound and read like the myths and stories they've heard before bed. What they hear is the same: a way to explain the universe.

Then there's Wheeler's question and Bhatia's response. If it's so simple, why wouldn't a child understand it? Why must we see them as difficult?