You could compare active vs passive reading to being active or passive about most anything.
The point is this: Are you waiting for things to come to you, or are you seeking them out with purpose?
Afterall, the point is not just to read.
The point is to learn, and from learning, to live a better life.
Quit waiting for life to happen to you.
Get a book.
Get a pen out (I use Evernote).
And get after it.
You, my friend, obviously already know that few things affect you like time alone with a good book, highlighter in hand. And the highlighter or pen is critical. We’re not sitting with the book in our hands, passively waiting for some profound words of wisdom to leap from the page; rather, we’re actively seeking wisdom. Even now, as you read these words, be on the lookout for something that will change everything. One idea has the power to transform your life forever, but you must first recognize it.
-Andy Andrews, The Seven Decisions