Reciprocity

I'm trying to wrap my head around the concept of reciprocity. On the mission this was easy because everything was contracted: we teach, you keep commitments, you feel something, and we teach more. However, how do you give back in a situation where you feel like you have nothing to give? I'm thinking mostly of the field study experience here. I'm going to research, so I will need their time/knowledge, but what will I give back? This question got me thinking about the simplest moments of reciprocity, which made me think of a man I met while jogging yesterday. This man and I had gotten caught at the same intersection, I had obviously been jogging and he was headed across the street to the library, at first we smiled at each other and nodded. After a few seconds I asked him how his day was going, he responded to my question and then nicely told me that the concrete sidewalks are hard on your knees while jogging. We then had a conversation where I learned about optimal jogging surfaces, about how he had completed five marathons, and the injury that was now keeping him from running. It was a great conversation that spanned all of two minutes. This cute little Hispanic man had knowledge to give, and all I had to offer was my attention and gratitude. As meager as my reciprocity was for his knowledge, I knew it still meant something to him. It's like those moments when you meet as strangers, but leave as friends. Time, appreciation, and gratitude are often the kind of reciprocity that builds bridges and motivates us to serve again.