If this question has an obvious answer, please excuse my ignorance. I'm still very new to the world of physics relative to most of you. But my question is simple. In Newtonian physics I know the rather simple explanation along with the corresponding formulas but in modern physics I'm a little confused. If gravity is just a distortion in spacetime which causes bodies to travel in a geodesic path along spacetime, why does that body accelerate? If a body just wants to remain traveling in a straight line at constant velocity, than why does "bending" that straight line result in acceleration. From my, very limited, understanding the body is still traveling in a locally straight path so what has actually changed that causes the acceleration? Thank you in advance.