What premise is set in the first two lines of the poem, Kindness?

The first two lines of, Kindness, establish a premise that runs throughout the poem: Before a person knows one thing, he or she must know something else. (The "you" in this work refers simply to the universal "you," or people in general, not to a specific person.) In this case, the real meaning of kindness, which seems easy to understand, is shown to be more complex than one may realize. The speaker suggests, ironically, that to "know what kindness really is," first "you must lose things."