Speed is relative

Take a time-traveling Ben Franklin for a ride in your Prius and you'll give him a heart attack.

Meanwhile, you're driving down the highway while eating a muffin and texting at the same time.

We can clearly get used to more than we expect. We can learn to live a space station orbiting the Earth, and we can learn to sit in zazen meditation for 18 hours without moving.

It's not what you are capable of. It's what are you hoping to accomplish...