I hold this to be the highest task of a bond between two people: that each should stand guard over the solitude of the other…
All companionship can consist only in the strengthening of two neighboring solitudes: when two people both give themselves up in order to come close to each other, there is no longer any ground beneath them and their being together is a continual falling…
Self-transformation is precisely what life is, and human relationships, which are an extract of life, are the most changeable of all, rising and falling from minute to minute. Lovers are those in whose relationship and contact no one moment resembles another.
There are such relationships which must be a very great, almost unbearable happiness, but they can occur only between very rich natures and between those who, each for himself, are richly ordered and composed. They can unite only two wide, deep, individual worlds.
For one human being to love another: that is perhaps the most difficult of all our tasks, the ultimate, the last test and proof, the work for which all other work is but preparation.
~ Rainer Maria Rilke (December 4, 1875–December 29, 1926)