It's normal to have this idea. Maybe one day. However, as far as I know, during the Olympic Games, the Ministry of Public Security organized various protective and preventive measures, and the strings of the Ministry of Public Security were very tight, ready to deal with the anti-terrorism task at any time. You just put your heart in your stomach. Hehe:-)
I study psychology. Psychology believes that the scenes in dreams are often irrelevant to reality, but the emotions expressed in dreams are often true. You dream of violence, perhaps because your life needs some unusual factors to break your quiet life. Know your situation specifically. Dreams themselves are meaningless for predicting the future.