“You'll never know everything about anything, especially something you love.”

Book Two in 'The Extraction of the Master', P/V, here Woland addresses Margarita
The Master and Margarita (1967)

Source: We Were Liars

Source: Malcolm X Speaks: Selected Speeches and Statements

Source: The Long Fall

Source: The Wise Man's Fear

Emperor Has No Clothes Award acceptance speech (2003)
Context: I am a reasonably emotional person, and I see no reason why that's incompatible with being a scientist. Even if we learn about how everything works, that doesn't mean anything at all. You can reduce how an impala leaps to a bunch of biomechanical equations. You can turn Bach into contrapuntal equations, and that doesn't reduce in the slightest our capacity to be moved by a gazelle leaping or Bach thundering. There is no reason to be less moved by nature around us simply because it's revealed to have more layers of complexity than we first observed.
The more important reason why people shouldn't be afraid is, we're never going to inadvertently go and explain everything. We may learn everything about something, and we may learn something about everything, but we're never going to learn everything about everything. When you study science, and especially these realms of the biology of what makes us human, what's clear is that every time you find out something, that brings up ten new questions, and half of those are better questions than you started with.

Sabei que, segundo o amor tiverdes,
Tereis o entendimento de meus versos.
As translated by Landeg White in The Collected Lyric Poems of Luis de Camoes (2016), p. 25
Lyric poetry, Sonnets, Enquanto quis Fortuna que tivesse