Clarity of mind (C [sub m]) is affected by any number of factors, but by far the most important is horniness, which might be designated by [sigma], for obvious anatomical reasons that Waterhouse finds amusing at this stage of his emotional development.
Horniness begins at zero at time t = t [sub 0] (immediately following ejaculation) and increases from there as a linear function of time:
The only way to drop it back to zero is to arrange another ejaculation. There is a critical threshold [sigma sub c] such that when [sigma] > [sigma sub c] it becomes impossible for Waterhouse to concentrate on anything, or, approximately,
which amounts to saying that the moment [sigma] rises above the threshold [sigma sub c] it becomes totally impossible for Waterhouse to break Nipponese cryptographic systems. This makes it impossible for him to achieve happiness (unless there is a pipe organ handy, which there isn't).