Initially the Daniel Equation may appear a bit obtuse, but those familiar with calculus and trigonometry will notice a few curious aspects:

The first integral of the equation, which is made entirely of sines (with what amount to frequency terms coming only in even multiples), is integrated from 0 to 2 pi, and so obviously the area under the curve of this equation must thus sum to zero despite it being an infinite series.
That this series relates to the stages of insight is obvious also.
The outer integral is dt (d time), and there is no time term in the equation at all.
Pondering those two facts may lead to illumination, perhaps.