Vannevar Bush has envisioned a device called “memex”. Based on how he described memex, I find memex highly overlapping with the web today and the functions of personal computers. I am surprised by how he predicted many kinds of technologies that we have in recent days. For example, he has predicted that “new forms of encyclopedias will appear”. I knew he is referring to online encyclopedias like Wikipedia, and then I suddenly realized this is written in 1945. This article made me feel the infinite potential of the web. It has been 77 years since this essay was published and he could foresee the technology we have today. I believe technology, especially the development of the web, will grow much crazier.