Upekkha and Non-attachment in Buddhism

I have read on Wikipedia, after an enlightening answer on here, that *upekkha* signifies not *total* indifference, but that : > The "far enemy" of Upekkha is greed and resentment, mind-states in obvious opposition. The "near enemy" (quality which superficially resembles Upekkha but is in fact more subtly in opposition to it), is (cold) indifference or apathy: one is not neutral after having engaged deeply with the wordly winds, **but due to having closed oneself off to many emotions related to these worldly winds**. Can anyone expand on this paragraph, and especially on that last part? Thank you.