阅读短文，并按照题目要求用英语回答问题。
I’m a 34-year-old man, married, lived in a nice house, and have a successful career as an educational consultant. But my life was not always so great. I had a learning disability from an early age. I went to a special school where I got plenty of extra help. Still, I suffered the rest of my school days in public schools.
My life improved remarkably when I discovered art. The art world gave me a chance to express myself without words. I went to a workshop and gradually got good at making things with clay(黏土). Here I learned my first important lesson: disabled as I was in language. I could still be smart and well express myself with clay. And my confidence came along.
I got my next lesson from rock climbing. It was a fun thing but I was scared from the start. I soon noticed it wasn’t a talent thing; it was practice. So I did it more. After about five years of climbing, I found myself in Yosemite Valley on a big wall. I learned that if you fall in love with something and do it all the time, you will get better at it.
Later I decided to apply my previous experience to learning how to read and write. Every day I practiced reading and writing, which I used to avoid as much as possible. After two hard years, I was literate.
Having gone through the long process with art, rock climbing, and reading and writing, now I’ve got to a point in my life where I know I am smart enough to dive into an area that is totally unknown, hard, but interesting.
What lesson did the author learn from rock climbing? (No more than 15 words)