"That - he said - nobody knows". It's kind of different from "we live in a sea of energy". I honestly think inertia is a lot easier to grasp than energy. It's a

"That - he said - nobody knows". It's kind of different from "we live in a sea of energy". I honestly think inertia is a lot easier to grasp than energy. It's a phenomenon you can experiment, describe and name, energy is more abstract.