You know when I was in Srirangam one Sri Vaishnava told me one very nice story. Once Ramanujacharya was doing some Parikrama there, then one devotee approaches him and says that , You know I have these financial problems. Can you please help me? Ramanujacharya told him that, Don't worry I will tell one of my secretaries and arrange for something to be done for you. So anyway there were so many people coming to meet Ramanujacharya and he forgets. It just skips from his mind. So, after a month he comes back to Srirangam after his preaching program and he sees that devotee. As soon as he sees him, Ramanujacharya, Oh my God!! I was supposed to make arrangements for this devotee. I forgot. And he goes up to this devotee and says, I'm sorry I was supposed to make arrangements for you. He said No no. In fact I'm grateful to you for all the arrangements that you have made.
Ramanujacharya says, I made?
Yes you made. You told your secretary that you make all these arrangements for me and since then I'm well settled. Thank you very much Ramanujacharya. And then Ramanujacharya understood that he had forgotten but the Lord remembered the commitment made by him and Sri Ranganath incarnated as Sri Ramanuja and fulfilled his promise.

So, the Lord always remembers each and every service. Even though we may forget, Lord never forgets. If you say that if the Lord cannot forget then how can He be God? Isn't it? Lord also forgets. What does He forget? He forgets all the sins that we have performed once you have become His devotee. Then He just accepts. Many a times we do the opposite. We remember all the offenses people have done to us and forget all the good things that people have done to us. But the Lord is totally opposite. When the Lord sees that somebody is doing some nice seva, even though it may be very insignificant, he exaggerates it and is very conscious of it. If somebody does something wrong then the Lord forgets it.