The Importance of Mass at High Speeds

"I think what you're saying is that like if i'm going really fast from here to Andromeda for example in one particular direction and i'm going at half the speed of light then my momentum in the direction  from here to Andromeda is really high. So it's really hard to like accelerate be more in the direction of Andromeda" "So force and acceleration no longer line up so f doesn't equal ma at very high velocities instead you have to use f equals change in momentum that's the real formula"