Appendix

Age two with my father
Age two with my father

*Yue Fei*—pocket picture-story book
*Yue Fei*—pocket picture-story book

In the mountain village—with my father's friend and a playmate
In the mountain village—with my father's friend and a playmate

Elementary-school graduation
Elementary-school graduation

Jianyang High—school gate (hometown visit)
Jianyang High—school gate (hometown visit)

Professor Strang's linear algebra class at MIT
Professor Strang's linear algebra class at MIT

Email from Ding Lei asking for my phone number—offering to set me up with a girlfriend
Email from Ding Lei asking for my phone number—offering to set me up with a girlfriend

Times Square subway—jam with two Spanish-speaking musicians
Times Square subway—jam with two Spanish-speaking musicians

At Wall Street
At Wall Street

In front of the White House—playing *Chengdu*
In front of the White House—playing *Chengdu*

(Chengdu is the song by Zhao Lei—a widely known Mandarin folk-pop ballad—not the city of Chengdu, Sichuan.)

Feodor—triple gold medalist in physics, astronomy, and mathematics—explaining a problem to other contestants; *Mathematics for AI and Machine Learning* (my book)
Feodor—triple gold medalist in physics, astronomy, and mathematics—explaining a problem to other contestants; *Mathematics for AI and Machine Learning* (my book)

For more photos, visit this book's companion site: https://above-the-clouds.2peanuts.com

Afterword—Three Thousand Years Later

In this book

there are people already famous—

or whom the world came to know later.

Some

for whom fame is still to come.

But this book

is not about who they became,

or who they would become.

Some things happened before the world saw them.

And some—

after they had broken through the clouds—

still met me in the mud.

Some taught in front of the blackboard.

Some wrote code in the office.

Some sang on stage.

Some were building something that had only just begun.

The roles were different.

The times were different.

But each encounter was real.

What made it onto the page is only part of the story.

Many people,

many things,

never got written in.

Some I couldn't bring myself to set down.

Some weren't mine to say too much about.

Some were always meant to stay with time.

What truly remains has never been only the words on paper.

The world remembers their names.

What I remember is how they stood among people—

not only how they looked from the heights.

This is not about fame.

Not about success or failure.

It is about the real connections between people—

across different heights,

different worlds,

and different times.

Three thousand years later,

perhaps

no one will know

whether they were people—

or something else.

Only traces remain—

of those who once walked here.