If you pray God for something and that he grants it to you, does that mean you are a good person and that your wish was fair?
God always knows what is best for us, even before we ask. When we pray, it is always good to pray as Jesus did when praying to the Father in the Garden of Gethsemane: "Not my will, but Thine be done."
No. It means that God willed what you were asking for - He said "yes".
Prayers are always answered, though sometimes not in the way we would like or are able to understand. I've heard people say that God gives three answers to prayers - 1. Yes; 2. No; 3. I've something better in mind... It's often only with hindsight that we realise that our prayers were indeed answered in the best way, even if the "no" seemed a bit unfair at the time!