It's a very foundational component of Leo's teachings. One cannot be following Leo's work without being radically open-minded. Also I found it's the key to successful contemplation and unlocking deep truths and insights.  However I discovered there is a huge problem.. The mind is fundamentally afraid of being open.. The mind has a natural tendency to be closed off from radical ideas or new possibilities. Because being closed minded is what grounds your sense of reality. You look at the world through a specific lense and you assume a bunch of things about the world that are basically unquestionable. You do this to survive. You can't survive if you assume that you know nothing and you're equally open to any information. As soon as you start entertaining new ideas and open your mind to change your entire worldview.. You start to feel like you are losing a part of what grounds your reality. This can be noticed for example with  religious people who are so attached to their beliefs.. and then they discover that religion is just bullshit and there is no sky daddy up there taking care of you.. Yeah that might send them to an existential crisis.
My question is what is the limit of open mindedness? Can one be open minded to literally anything? Is that how you reach truth? But what you notice is if you are Infinitely open minded.. You will just end up knowing nothing and not able to know a thing.  There must be a balance. But where do we draw the line? Can you open your mind to the following possibilities :
1 that you have no brain or any internal organs. Literally. After all have you ever seen them? 
2 that you are the only conscious being in the entire universe and everyone else are just figments of your mind.
3 that Leo is an alien not a human.
4 that your mom got born out of a chicken.(that's an example from Leo's open-mindedness video lol).
5 that the world ceases to exist as soon you stop looking and gets rendered once again when you look again . Like a video game.
5that the flying spaghetti monster is real. He created this world. And he will punish you if you don't worship him in this life.
6 that the entire world that you can see through the media is not real.
7 that their might be a space Kangaroo standing behind you your entire life but you couldn't see him cuz he turns with you
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Can you honestly open your mind and entertain such ideas?  Notice the emotional  reaction against some of these ideas. and notice that you can't actually disprove any of them with 100% certainty.
You can't open your mind to these possibilities not because they are false(you don't know that) or because they are stupid lol.. But because they will threaten your sense of reality and everything you thought you know about the world might get thrown out the window. It's like you have to be close minded to survive . What would happen if you become infinitely open minded?