“People do not decide to become extraordinary. They decide to accomplish extraordinary things.”
– Sir Edmund Hillary [1919-2008]

... most passenger jets fly between around 9,448.8 m [31,000 ft] and 11,277.6 m [37,000 ft] depending on their weight and the distance being flown, however the smaller business jets typically operate up to 13,716 m [45,000 ft] and in the case of Concorde it went as high as 15,544.8 m [51,000 ft]. At those kinds of altitudes you can see the curvature of the earth. The reason is that at high altitudes in less dense atmosphere jet engines work more efficiently by burning a lot less fuel and the ground speed of the aircraft is significantly higher.