This book is dedicated, in respect and admiration, to the spirit that lives in the computer.

I think that it's extraordinarily important that we in computer science keep fun in computing. When it started out, it was an awful lot of fun. Of course, the paying customers got shafted every now and then, and after a while we began to take their complaints seriously. We began to feel as if we really were responsible for the successful, error-free perfect use of these machines. I don't think we are. I think we're responsible for stretching them, setting them off in new directions, and keeping fun in the house. I hope the field of computer science never loses its sense of fun. Above all, I hope we don't become missionaries. Don't feel as if you're Bible salesmen. The world has too many of those already. What you know about computing other people will learn. Don't feel as if the key to successful computing is only in your hands. What's in your hands, I think and hope, is intelligence: the ability to see the machine as more than when you were first led up to it, that you can make it more.

上面是sicp的卷首语，我认为这段话道出了从事计算机专业的最重要的理由，那就是“快乐”二字。

编程是一件很有意思的事情，当你看到自己辛辛苦苦编写和调试的代码终于能够正常运行时，那种快乐和成就感是非凡的，也是其他任何行业无法比拟的。

朋友，你能感受到计算机带给你的快乐吗？如果能，请保持这种“for fun”的精神，如果不能，那么你应该试着找回那份单纯的快乐，或者，离开这个行业，去做一些别的事情。