Definitely a good point. I live in a college town and know many people that read all the time, but don't actually do anything active with what they've read. They just consume it continuously and think the understand many topics. Except when you talk to them, it comes out quickly that they didn't actually understand what they read on a deep level, they just went along for the "thinking ride".

And, as you point out, if you push yourself to read actively, it helps a lot!