There is a thread with a fun name at High Rankings Forum named False Gods. The thread discusses how when searching for some "ego keywords" (keywords a person wants to rank well for) he found himself ranking well. But then he noticed that Google personalized search was turned on.
The results within personalized search, no matter which search engine, are tailored to your liking. So if you want to be number one for "seo" you can be over time. Especially if you use the remove result function until your site is #1 and also if you tend to click on your pages more often than others.
Past related article on this that may be of interest is named Search Engine Optimization is Changing So Quickly.
Forum discussion at High Rankings Forum.