What exactly is a false flag event ?

It's applied to terrorist events where the real perpetrators aren't the ones the TV and media report but instead it's actually the government that is supposed to be protecting its people.

Why would a government do such an evil thing ?
Very good question. It means that the government and especially the media have been taken over by either some foreign power and so is using it to achieve some agenda it wants to pursue. Or there are some evil elements in society that have control of government and media , and again using them to pursue a hidden agenda that benefits them. These elements are sometimes referred to as the Elite.
The masses are oblivious to this and have already been programmed to believe everything the TV and mainstream media say. Hence they will automatically fall for the official narrative and will find it almost impossible to question it. The programming has been done so well. There are specialists in how to programme the masses. And it's done very gradually over time so people don't notice it. Especially over the news and in popular films created for such purposes. So the hypnosis is very strong.

What can people do to come out of hypnosis ?
A very good question and also a difficult one. The best way I think is to change your way of living by making the search for truth to be the upper most. Search for truth on all issues. Especially the most important. Eg why I am here , is God really evil, do I have a soul and then all things below that. This , I believe , is the best way to immunise yourself against being fooled via the media. Because you will building up your own version of what the truth is and not reliant on the TV to tell what the truth is everyday. But obviously it's a difficult path and hence why the TV conditioning is so powerful. Because it's much easier to take the truth from someone else (the TV) rather than to research it yourself.

However if you wanted an easier path then just look at YouTube or google for info on false flags and see how they were used in the past. Eg Hitler or the US to bring about the Vietnam war , or 911 to bring about the war on terror and so on.  You may find that it was an easy way to convince the masses that a new war needs to start up somewhere. Using fear to control emotion. It's a popular technique and most effective. When I researched 911 I found the evidence overwhelming that it was an inside job.

So at the end it boils down to doing your own research and not taking the easy way out of just believing the TV and media. Instead become suspicious and doubtful of them and research for yourself. Become suspicious and doubtful of all. Myself included. Doubt is the path to certainty ( a popular Sufi saying).

Good luck to you. Only the brave can take such challenges. But know that it is worth it. Worth the effort. And be ready to be transformed into a better version of yourself. The truth uplifts us when we seek it.

Peace