It seems to me that all our sadnesses are moments of tension that we feel as paralysis because we can no longer experience our banished feelings. Because we are alone with the unfamiliar presence that has entered us, because we feel momentarily abandoned by what we’ve believed and grown accustomed to; because we can’t keep standing as the ground shifts under our feet. That is why the sadness passes over like a wave. The new presence inside us, that which has come to us, has entered our heart, has found its way to its innermost chamber, and is no longer even there—it is already in our blood. And we don’t know what it was. We could easily be persuaded that nothing happened, and yet something has changed inside us, as a house changes when a guest comes into it. We cannot say who has entered, we may never know, but there are many indications that the future enters us in just this way, to transform itself within us long before it happens. That is why it is so important to be alone and attentive when you are sad: because the seemingly uneventful and motionless moment when our future steps into us is so much closer to life than any loud and accidental point of time which occurs, as it were, from the outside.
Rainer Maria Rilke, Letters to a Young Poet