All of Kabbalah speaks about this, but it is perhaps the most important thing

You see our minds have three basic states

The open state is like a child (who has security) in their fantasy they can and will be (as Jerry Seinfeld says, when boys read comics they are choosing jobs.)

The closed state is fear – in this state we have the need to protect ourselves – it creates rigidity, perfectionism; and little things become very big to us – so it is exactly opposite to the open state – the former, little things don’t bother us, because in any event we will…

then there is the medium state, for in-between fantasy and fear, lies truth