I was born in, so I was "in" against my choice for quite some time. I never bought that Jehovah nonsense. However, at some point I decided to give it a try and learn a good life lesson about trusting my own instincts. When I decided that I wanted to leave, I figured that I cannot just walk away from the first 23 years of my life. I needed to prepare. My departure was gradual, especially since it was important to me to leave in my terms and because I said so, not because of their stupid shunning practices. That took planning and patience, so that's why I stayed "in".
I am aware of research that has been conducted in cults and other oppressive groups and relationships, and what they show is that the main reasons people stay are:
They continue to believe in the cult teachings or leadership
To protect their investment
To hold onto family
Some other relationships can be real and solid
Pride / embarrassment
Fear
I had none of those reasons for me to stay, I grew up in a rather bad family environment, one that I needed to protect myself from. I never bought that paradise on Earth crap. Actually, the belief that I have the most problem with is one that it's not unique of the WT. I never cared about the concept of Satan, always found it too contrived and convenient.
I never had any friends or strong relationships with anyone, reflecting and looking back, I think that there were so many people pushing so hard to deny their realities of their sad pathetic lives, that I can see how a person like me would make them feel uneasy.
I was more embarrassed for being seen preaching, even though I was raised doing that and I was quite good at it, than anything else. Also since I was born in, I felt that it wasn't my decision to join them, so leaving them felt quite an easy decision in that sense, that is, that wasn't my choice, I'm out.
I was never afraid of "the world". I felt that my life started the moment I decided to leave the JWs. And I was quite right.