Some people have a hard time imagining how big the search space is. It is clear here from using "trillions upon trillions" too. To put simply you are thinking in terms of a grain of sand compared to all the sand in the world.
Here is a trillion compared to 2²⁵⁶ which is about the number of private keys there are. It helps you visualize how ridiculous it is even if you search "trillions upon trillions" of keys!