There are surprisingly many good poems which are anonymous. These can be anonymous (unknown writer) for a variety of reasons and rarely impact upon their worth as a poem.
All these quotes are indexed as anonymous but where appropriate they have been credited at the foot of the text. They are not poems but mere quotes that could be used, say in a speech at a wedding or on a romantic card.
For one human being to love another that is perhaps the most difficult of our tasks; the ultimate, the last test and proof; the work for which all other work is but preparation.
~ Rainer Maria Rilke