If ever there were important discoveries they are these.
The Buddha said there are three marks of existence – impermanance, suffering and no-self. Everything (yes, everything) in the world is impermanent. There are no exceptions to this. We suffer because we think there is something permanent. It doesn’t matter what that thing is, if one thinks it is permanent then we suffer the consequences for that belief. More often than not the thing we believe most to be permanent is the self. And The Buddha unequivocally states even this is impermanent.
Know that there is no self would end suffering which in turn leads to the understanding of impermanence.
But coming to this understanding is harder than it sounds. It usually takes years of training. When you have achieved this, though, rest assured you will be enlightened. Good to know, isn’t it.