Pensée unique is a big fancy word that means "thinking the same thing as everyone else". It's like when all your friends wear the same clothes or like the same things, and you feel like you have to do it too, even if you don't really want to.
Sometimes, people can get stuck in pensée unique and they don't realize that there might be other ideas or opinions out there. This can happen because they are only exposed to one way of thinking, or because they feel like they have to fit in with a certain group.
But it's important to remember that it's okay to have your own opinions and ideas, even if they are different from other people's. It's actually really good to have different perspectives because it can help us learn and grow. So, if you ever feel like you're stuck in pensée unique, try to think for yourself and consider other points of view.