Simplicity and Difficulty are Orthogonal
from Einstein's explanation of covariant tensors. Beautifully simple but formidable to comprehend. Or Haskell code:
defining Fibonacci numbers as an infinite lazy list. Again, elegantly simple but hard to understand for the uninitiated.
Nevertheless, this is far better than the alternative, which is complicatedness. As C.A.R. Hoare remarked, "There are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies. The first method is far more difficult."