Correct. The phenomenon I described only applies to moving ahead in time. To achieve it requires the addition of a LOT of energy. A high level of energy is required in order to sufficiently change ones state of motion, actually their velocity. Velocity is a two component vector consisting of magnitude and direction. Change one or the other, or both, sufficiently and you will noticeably move ahead in time, as compared to your stationary surroundings. The law of inertia states that objects with mass will continue moving along in a straight line at a constant rate of speed unless acted upon by an outside force. Energy = Force x Distance
That's true in a flat space-time. In the world of full relativity, inertia means you move along geodesics in spacetime, which is Riemannian geometry for our "straight."
IIRC, of course. It's been a while.
One of my favorite SG stories had to do with relative motion and the use of a pool table. The scientist said he could eliminate all motion in an object with his beam. Everyone scoffed at him. He said he’d prove it with a game of pool.
His biggest scoffer ended with a hole in his body the size of the pool ball. The motion had been stopped relative to everyone in the room, the earth, the sun, the galaxy.... That ball in relative terms, stopped as it was, was very, very fast...