Studying the Bible and applying it is not in fact common sense. What if the Bible was not written for our day, but someone is merely misapplying it to suit their own agenda? Or, maybe one or more of the writers misapplied things as literal when it was supposed to be a parable? If you are going to study the Bible and apply it, then I highly recommend doing just what the Watchtower Society banned last September and study it independently or in small groups.
Choosing associates wisely is in fact intelligent. You would not want to associate with a group of people that only want to see how many drugs they can get you to do. You also would not want a group that wants to mislead you and control everything you do all the time. You want a group that encourages you and makes allowances for you to mess up. You learn from mistakes, and a too-controling group will not let you learn that way.
And learning from experiences is something I have seen the witlesses have a miserable time with. Hardly any of them learn from experience. They only learn from the littera-trash from the Witchtower Society. I have seen many of them have pxxx poor results one day and try the exact same system the next day, and wonder why they are getting pxxx poor results again. People will keep going back out day after day, doing the exact same thing. They go to the boasting sessions every time, hoping for something that never comes. And they keep doing the same things, hoping for different results.
Not something I recommend doing the Watchtower way. To gain common sense, you need a measure of independence that is not granted by the Tower. Make your mistakes and figure out what went wrong. Study the Bible if you want to follow it, but do so independently. And shun groups that are only out to fill a nefarious agenda. And that especially goes for the Watchtower Society.