In 2000-2001, I used to do tech support for Microsoft, supporting the worst of all of their operating systems, Window ME. When I started, Google Search was not well known. We had to find answers by getting lucky on some other search engine, and it was extremely unreliable. Then, about a year into it, Google Search started to become popular. The resolution for even the most simple problems was only a Google Search away. The job got much easier, very quickly.
I remember the first time I was able to enter the exact text from an error, and find the answer on some obscure blog. Google has changed the way we find thing. Correction, it has made it possible to find what we are looking for.
This video demonstrates one of the reasons that I believe that Google Search is the most important app ever written.