Inertia is not a concept, it's a name for the reason cars have seat belts, for why your blood goes into your fingers when you spin around with your arms outstre

Inertia is not a concept, it's a name for the reason cars have seat belts, for why your blood goes into your fingers when you spin around with your arms outstretched. We don't really know what/why it is, but there's nothing abstract about it and it's not conceptual. Flywheels are inertia.