Valfarly chanced upon wikipedia and thought "that'll never work"... but after using it a few times, he eventually got sufficently annoyed by a typo to do something about it and on 15th March 2004 hit edit. From there it was a slippery slope to writing articles for things he found no-one else had written about and adding tidbits, factoids and other nuggets of information to previously covered topics. Finds himself correcting spelling and grammar far too often!
If you would like to edit Wikipedia, just click the [Edit] tab (to use VisualEditor which is a WYSIWYG editor) or click the [Edit source] tab to use the Wikipedia text editor. Both tabs are at the top of the desired page or page section.
To create a new article, type the name of the topic in the search box and press ↵ Enter. If a page doesn't already exist with that name, Wikipedia will let you create one. Follow the instructions on the screen. As an alternative, the Wikipedia Article Wizard helps you through the process of submitting a new article to Wikipedia. Redlinks are another way to create new articles. Mouse click on the red link and Wikipedia will let you create a new article with that name.