Wikipedia is open for business 24/7/365, recording the sum of human knowledge in real time. There are thousands of editors, millions of pages, and billions of editing opportunities. It can all get a little overwhelming!
Hence a perspective adopted by many editors, represented by an essay that says it all: "There is no deadline." Don't feel hurried, don't get flustered. Just do what you can, and don't worry that everything isn't always just right. It never will be, but given time, we'll get closer.
Some bureaucratic actions do have deadlines, such as nominating articles to be featured on the main page. However, the unhurried default state is necessary to maintain sanity.
It also extends naturally from two other key facets of Wikipedia. First, the content is written by volunteers. Second, as a digital encyclopedia with no print edition, there literally is no deadline.