Explanation is to cognition as orgasm is to reproduction.

--- Alison Gopnik, Explanation as Orgasm, Minds and Machines 8 (1) 101-118 (1998)

In context:

"My hypothesis will be that explanation is to cognition as orgasm is to reproduction. It is the phenomenological mark of the fulfillment of an evolutionarily determined drive. From our phenomenological point of view, it may seem to us that we construct and use theories in order to achieve explanation or have sex in order to achieve orgasm. From an evolutionary point of view, however, the relation is reversed, we experience orgasms and explanations to ensure that we make babies and theories."