some pages are specific to one topic that answers one question. The user can leave now.
Then there's visitors whose IPs change each time they hit a link - these appear as multiple onepage visits in stats - not sure if GA can track these types of visitors (aol is one, some larger US internet companies another) or if like Statcounter, they show multiple visits since they track by IP.
And then how are visitors who come to your site, read a few pages and then seem to go , but leave your page open in the browser window and pop back in every few days over a week and look around some more - does bounce rate show the initial visit as one, short and bounce and then the next day, a two page 1 minute visit and go back and amend the original view from the day before?
Anyhow I don't worry about bounce rate all that much - GA says some of my pages have a 90 percent bounce and others a 0 percent bounce