…you must not let yourself be diverted out of your solitude by the fact that something in you wants to escape from it. Precisely this desire, if you use it calmly and judiciously, as a kind of tool, will help you to extend your solitude over a greater expanse of ground. People have tended (with the help of conventions) to resolve everything in the direction of easiness, of the light, and on the lightest side of the light; but it is clear that we must hold to the heavy, the difficult. All living things do this, everything in nature grows and defends itself according to its kind and is a distinct creature from out of its own resources, strives to be so at any cost and in the face of all resistance. We know little, but that we must hold fast to what is difficult is a certainty that will never forsake us. It is good to be alone, for solitude is difficult; that something is difficult should be one more reason to do it.

—Rainer Maria Rilke (translated by Charlie Louth)
—found in Letters to a Young Poet (written 1902-1908; first published 1929; this translation 2011)