The good poet welds his theft into a whole of feeling which is unique, utterly different from that from which it was torn; the bad poet throws it into something which has no cohesion.
In one's youth every person and every event appear to be unique. With age one becomes much more aware that similar events recur. Later on, one is less often delighted or surprised, but also less disappointed than in earlier years.
Every word instantly becomes a concept precisely insofar as it is not supposed to serve as a reminder of the unique and entirely individual original experience to which it owes its origin; but rather, a word becomes a concept insofar as it simultaneously has to fit countless more or less similar cases -- which means, purely and simply, cases which are never equal and thus altogether unequal.