|This page in a nutshell: If you can't write an article after leaving all your prior knowledge about the subject behind, it fails the amnesia test, and regardless of how many external links you can dig up that relate to the subject, those links don't satisfy notability guidelines.|
If you're thinking of starting an article about something, chances are you know a bit about it already. But editors that have been around Wikipedia for a while will know that many articles are deleted for failing to satisfy the notability criteria in enough a number of Wikipedians to vindicate such action. So, before creating the article, they may try to make sure that if the article is nominated for deletion, they can satisfy Wikipedia's myriad notability guidelines (including WP:WEB, WP:BIO, WP:CORP, WP:MUSIC, WP:WINI, and so on).
If you do a Google search for most subjects, you'll usually turn up something that could, at first glance, appear to help your article meet Wikipedia's criteria for notability, specifically "significant press coverage" (WP:BIO), "multiple non-trivial published works" (WP:WEB, WP:CORP) and the like, and thus be safe from Wikipedia:Articles for deletion. Nonetheless, before you start creating the article, it's a good idea to take the following steps:
- Forget everything you know about the subject (or act as though you know absolutely nothing about the subject).
- Re-read the 'non-trivial published works' and 'press coverage' you found, and learn everything you can.
- Start writing your article, using only information from the sources that you found. If you find that you have nothing to write, don't write anything.
The notability guidelines are there as a means to ensuring that an article can be verifiable (which requires reliable sources) and neutral (which requires at least one person independent of the subject who thinks it's worth writing and maintaining an article on them). Meeting them is not a standard for inclusion.
The Amnesia test is also useful when participating in Articles for deletion discussions.