…you must realize that in this life it will be impossible to continue in this work [of contemplation] with the same intensity all the time. Sickness, afflictions of body and mind, and countless other necessities of nature will often leave you indisposed and keep you from its heights. Yet, at the same time, I counsel you to remain at it always either in earnest or, as it were, playfully. What I mean is that through desire you can remain with it even when other things intervene.
— Anonymous, The Cloud of Unknowing (translated by William Johnston)