Peer-to-peer file sharing systems, most notably Bit-Torrent (BT), have achieved tremendous success among Internet users. Recent studies suggest that the long-term relationships among BT peers can be explored to enhance the downloading performance; for example, the cooperation of peers to re-share old contents. However, whether such relationships can be built still remain unknown. In this paper, we take a first step towards the real-world applicability of the content re-sharing through a measurement based study. We find that 95% peers cannot even meet each other again in the BT networks; therefore, most peers can hardly be organized for further cooperation. This result is contradict to the conventional understanding based on the observed daily arrival pattern in peer-to-peer networks. To better understand this, we revisit the arrival of BT peers as well as their long-range dependence. We find that the peers' arrival patterns are highly diverse; only a limited number of peers have very clear self-similar and periodic daily arrival features (which we call them stable peers). The arrivals of other peers are, however, quite random with the clear absence of long-range dependence.