What does mind-boggling mean?

"Mind-boggling" means something that is so surprising, impressive, or confusing that it is difficult to comprehend or understand. It's often used to describe things that are:

* Extremely large or complex: "The sheer size of the universe is mind-boggling."

* Unbelievable or extraordinary: "The magician's tricks were mind-boggling."

* Difficult to grasp conceptually: "Quantum physics is mind-boggling to most people."

Essentially, it implies a feeling of overwhelming astonishment or bewilderment.