Maybe a fair judge of mental difficulty would say "you gotta write at least the loop invariant" (termination being too pedantically obvious) -- though admittedly I leave it out more than I used to.

When I was introduced to sorting as a new programmer, via bubblesort, I thought "why that way?" and came up with selection sort as a method that made more obvious sense. It seems to me like bubblesort's alleged intuitiveness is post hoc from the shortness of the code in terms of all-ascending for-next loops -- the intuitive reason it worked was just that the inner loop did move the next max into place just like selection sort, but with extra swaps along the way.