No. The majority don't. And they don't care. For them, faith in the doctrine is more important and desirable than understanding the doctrine itself.
When I was in, I was fairly studious. I didn't particularly enjoy keeping up with the regular scheduled study (School/Service Meeting; Bookstudy; Watchtower) although I did anyway. But what I really enjoyed was the personal study. I was always wondering about certain issues or points and wanting to get the "Slaves" clarification on the matter. (It was these habits that led to my exit hehe) So I could explain all the deeper issues fairly well, and i was up on all the "New Light". I wasn't doing anything remarkable, I was doing what was requested of us by the Society.
But what was amazing was how I was constantly surprised at how several Elders didn't know how to explain even simple things, and how superficial their knoweledge was. Many of them regularly spouted "Old Light" from the platform. I remember one Elder making a huge deal out of how he 'just found out' who/what the "Prince of Persia" is!!! I was thinking... "I knew that when I was 15. WTF?" Another Elder seemed, from hearing him talk, like he had just finished the 'Knoweledge' book and became an unbaptized publisher. And that was about the depth of his knoweledge.
On my exit, I was also suprised at how I would explain my problems on certain doctrines to brothers and they'd say, "Well I havn't researched that in a while." I could tell they didn't even know the BASIS for the doctrine let alone understand it enough to comprehend the problem I had with it!!!! Ahhh! It was frustrating... They were putting faith in these beliefs simply because the MEN on the GB said so. I even had certain individual tell me "I don't care... I don't need to know the details to believe it."
And that just highlights my original point... For them, faith in the doctrine is more important and desirable than understanding the doctrine itself.
I can't do that. That's not how I roll.