Paste and Match Style on Mac
On the Mac, the paste function associated with the ⌘V (Command + V) keyboard shortcut has a side effect: if you’re writing a document and you paste something from your clipboard, the document’s style won’t be automatically matched.
Here’s a quick way to fix this:
http://thaweesak.com/2009/06/15/setting-paste-and-match-style-as-default/