At 60km/hr, with fantastic reactions of 0.7 of a second, you will travel over 12 meters before you even get on the brake.
At 80km/h its nearly 16 meters.
Then you have to actually get the brakes working and stop without falling off.
Most people take about 1.5 seconds to react, but you are more clever, right? First, you have to identify it is a hazard, then react, so there's two things there.
Do you have any idea of how much road you will use up to stop?
Start paying attention to how long it takes you to react to any traffic situation, at various times of the day.
Buy a box of chalk and a tape measure
Go pace out these distances and look at them.
Then go and see how far it takes you to stop from either speed.
Pace it out. Walk the entire length up and back and absorb just how much road length is consumed by the process of see-react-brake-stop.
Incorporate this in your riding strategy.
If you reckon you are better than average, then the distances at the top of the page must be for you. The rest of us will double them.
It’s also the mathematics and physics that give a good reason not to tailgate and also keeps things smooth to have the buffer space. You can always speed up on exit.
In studies comparing younger and older car drivers, the older drivers outperformed the young drivers and had less crashes.
The young had better reactions, but the older drivers simply made better decisions and used better judgement skills about distances and situations.
Can you stop in a curve? At a goodly lean angle? What distance does it take? What part does countersteering play?