An excerpt from Letter 7 written by Rainer Maria Rilke in 1902:

For one human being to love another, this 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. For this reason young people, who are beginners in everything, cannot yet know love: they have to learn it.

But young people err so often and so grievously in this: that they (in whose nature it lies to have no patience) fling themselves at each other when love takes possession of them, scatter themselves, just as they are, in all their untidiness, disorder, confusion…. and then what? What is life to do with this heap of half-battered existence which they call their communion and which they would gladly call their happiness