Direct relationship between speed, control input, and G force.
The faster you are, or the bigger the input, the more G's you'll feel.
Picture a common Elevator in a tall building. When it starts up, your moving, changing state from being at rest, to traveling Upward. So you feel a little G bump, pulling you down, maybe flexing your knees. Your not moving real fast, so the gee's felt are not that strong. As that acceleration upward continues you feel "heavy"
As the elevator starts slowing down for its stop, you'll feel negitive gee's. Its been moving you up steady, now it cuts the gas, reducing the input. You feel "light" for a second.
Now take that elevator and instead of moving at 5 miles an hour put wings on it and its moving at 3-400 mph.
What happens when you pull the stick back and it goes up? Its going up a mile in seconds.
Righto, blackout, 6 Gee's. And if you pushed the stick forward, same thing, only redout. Shoves the fluid in your body into your head. (Can pop blood vessels in your eyes btw)