# What is the origin of pseudo force in non-inertial frames? [duplicate]

When a bus stops suddenly, I can "feel" a force pushing me. This is exactly as if someone really pushed me. Same is the case while doing a turn in a car, I can "feel" a force pushing me away from the centre. Also, why don't we feel the inward centripetal force but only the outward centrifugal force? If its only because of inertia, then why aren't they considered real forces since inertia is a fundamental property of matter. Everywhere I've read it says that pseudo forces are only incorporated to validate Newton's second law in non - inertial frames. But if they're not actual physical forces, then what is the force that I "feel"? Is there any other cause for pseudo forces other than inertia?