I was reading stuff on fictitious forces and encountered a section that said that gravity was a fictitious force. I read a couple of websites but still didn't find a clear enough explanation on why this is true? Also, if gravity is a fictitious force, then doesn't that mean that so long as we're under its influence we are in an non-inertial frame of reference? Then how is it possible that we achieve an inertial frame of reference on earth if we're always accelerating? Thanks.