Not everyone of us is good at numbers. However, when people hurt us, it's easy for us to count people's mistakes towards us. We are keeping the hurt to ourselves, and it cause bitterness in our hearts. On the other side, people who are always jealous of others and know that they often hurt others, also have this paranoia that people will hurt them. Jealousy can also cause bitterness in someone's heart. It can lead someone to make assumption based on nothing but worry and anxiousness. 

Jesus asked us to forgive others seventy times seven. It does not mean you have to count how many times you forgive others. It means you have to constantly release forgiveness. Even when you make mistakes daily, God forgives you. Jesus is asking you to follow his footsteps, to forgive others without keep counting on how many times you do it. Yes, it can be difficult for us to release forgiveness towards others. Yet that's the time when you can ask the Holy Spirit to grant others forgiveness and forget the mistakes that people do to you. 

Don't let bitterness tied down your heart. It will keep you away from God, instead. Let God get closer to you by realising forgiveness.