Sometimes, the heart just sinks hearing or knowing something. Something you didn't expect and about something that is close to you and usually it is a big opportunity loss. There is no question of getting angry or taking revenge, since it is a one way loss where only you are the only one hurt and you anyway don't want to cause harm to the other party in any way. Sometimes, there is disappointment and sometimes, not even that, just a sense of loss. One can't really do anything about it. Just accept it and be ready for such things in the future so that it doesn't hurt you as much as it did the previous time.