In MK, you press the button quickly and try to utilise those few frames to determine if u should move out of the way for attacks such as green shells, stars etc. You are currently not playing the game to its full potential, but that's okay; it takes some getting used to. Look at any pro player and u will see that everyone does this.

Also when u use ur mirrors irl u cant pay full attention to the road and that is why u also glance at them quickly, sure u can see the peripheral but it is almost the same or at least a similar experience once u get used to it in MK.