morahrach, you obviously were never truly mochel those few dollars which means he is still obligated to pay you. just cuz he forgot doesnt make him patur. i once had to tell someone i worked for he owed me an extra hour worth of my time i felt bed because i had left and so much time had passed since (not 6 years) but it continued to bother me ever so slightly eventho i was mochel. so i asked another employee at that office and she said he would want you to tell him and not be mochel. so when i told him he was so happy that i did becuase otherwise its considered stealing. and hes such a yashardik man that he really was happy i came to him to make things right so either be mochel ENTIRELY (hard to do) or tell him becuase if its really bothering you it can chas veshalom cause something up in shamayim for him.
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