I don't think, I know for a fact that mine was when we received a letter from a now released prisoner of conscience. I am a member of Amnesty and we write letters to government of different countries asking them to release prisoners we feel have been put in jail for fighting for freedom/rights/equality. So we had written a letter to this one government (name undisclosed) and after 3 months we got a letter from a just freed prisoner, saying "The only reason I was freed was because of those letters." Our task was finally rewarded, I just felt sooooooooo good that day, so far that's my happiest moment.