why angry?

To me, there are many reasons why people get angry. It can be because of jealousy, pride or impatient. But the usual reason is because of one's expectation not being met. For my case, I get fed up when people do not reply sms or return call. I find it so rude not to reply sms. Busy is not an excuse.. If one is busy, the most he/she can do is to send an sms saying he/she is busy now, will get back to you later.. How long can a sms reply take? Or would you rather just keep the other party waiting for your reply. My expectation is for people to at least reply. But different people have different expectations and that leads to anger and eventually argument. 1 minute of angry = 60 secs of happiness gone.. Whatever it is, I've learnt to be merciful, forgiving and always put reconciliation in first priority. In Matthew 5, people think that only when you murder, will you face judgment. But according to God, when you are angry, you will face judgment, don't even talk about murder. Is there someone you are not reconciled with?