As with many pieces of writing, this poem can be interpreted in different ways based on the reader. For example, many of us have gone through something tragic or lost something or someone that we hold to be a part of us. Or, there are times we get so caught up with life that we don't notice ourselves changing- for the better or the worse. Whatever that special "part of you" is, losing it, like the speaker did in the poem, can sometimes (but not always) result in bitter feelings and hurt. But, sometimes it is all for the better, because  as the saying goes, " if you really love something let it go...".