This is not actually made by me, I just designed the text, which is a quote from a man who made a deep impression on me when I saw his lecture on YouTube. Here is the lecture, which I hope you will find as fascinating as I did. The part where I took the quote from is around the 17 minute mark.
Here is the text on a shirt. I'm ordering the one shown here, but you can get the text on many different types of shirts. And to be honest, yes, I do get a small royalty, if someone orders a shirt I designed. However, my main purpose was to get the shirt for myself, but I made it public in case someone else likes the quote as much as I do.