• you understand the common browsing and editing words/terms/phrases/idioms, e.g.

location box, URL, hyperlinks, navigating away, browser window, tabs, menu, popup blocker, enabling cookie, right click, context menu, select text, copy/cut-paste, Ctrl-a, Ctrl-c/x/v. 

• you always read (popup) messages before clicking on Ok/Save/Submit/Cancel buttons!
• you can navigate around and find your way through a site even if the provided online help is not sufficient.