Yes, your wish should be something positive that you can accomplish yourself – you cannot force wishes on others. Let me give you an example:
Two people both wish to meet their idol. Fan number one writes in her Wishbook that the idol’s car broke down outside their house and the idol came knocking on her door. Fan number two writes that she wrote a song and sent a demo to the idol’s production company. When she had almost given up hope about ever hearing anything from them, she received an email saying that her idol wanted to record her song and for her to produce it.
Which one is more likely to come true?
