Have you noticed that when you publish one item in a single language Sitecore reports "Processed: 2"? Did you know that every time you publish, Sitecore secretly processes some items you didn't ask for? This is actually a feature designed to maintain the integrity of your content and that's obviously a good thing, but in practice I've often found it to be overkill. This post explains why Sitecore includes this behavior and should help you decide whether or not to disable it.