No one should blame themselves for not knowing more if they were once a JW.
The Watchtower is oppressive in its demand that members avoid educating themselves, using critical methods for Scripture study, and avoiding learning from other religions by actual participation. Telling members they can't even have thoughts that are contrary to Governing Body teachings or have to avoid contact with atheists, agnostics, or other religious people and their customs destroys what is so vital to the human mind and spirit.
And while the New Testament may not be as idiotic as it looked to us once rejected the Watchtower (because leaving the JWs behind often makes a person want to throw out both "baby and the bath water"), it doesn't have to be stupid or illogical to be untrue. I for one think there's a lot of intelligence clearly displayed by its writers, but I don't buy into its theology or its claims one bit.
Watchtowerism teaches people to live by polarized standards. So sometimes when we leave the JWs behind we think we can only be totally rejecting G-d and Scripture or make a stand for it in some way. If we reject it we may carry over the JW habit of saying that rejecting something requires it to be unreal or illogical. That's a Watchtower concept, and it is not true. I believe, for example, that Jesus of Nazareth was historical. That doesn't mean that I accept him as the Messiah or require that I give credence to the claims of Christians about Jesus.
You can reject what is real and logical, and still be real and logical yourself. The two are not exclusive opposites as the Watchtower teaches.
Not everything that is logical has to be accepted. You can have cancer. Cancer is fatal. You don't have to accept that you have to give in to the disease. You can put up a fight. Your fight can beat the odds, even when doctors read real data that says you won't make it. Sometimes science doesn't have the answers or the results don't matter. Sometimes when we say "no, I won't be beat" it means just that. And despite the best data and evidence you don't die and you do beat cancer, contrary to what science may say.
The world is not black and white. You don't have to make the Bible out to be a book of illogical stupidity to reject it. G-d can be real and you can still tell G-d: "No thanks, but I don't want to worship you." G-d doesn't have to not exist for you to reject G-d. In fact it's easier to reject something fake than something that isn't. And it isn't wrong to reject someone or something that is very real. Sometimes these things don't matter to you or aren't your thing. They don't stop existing once we reject them, so neither does their existence mean we have to accept them.
There are a lot of steps to take in removing oneself from the Watchtower. Leaving is sometimes the easiest part. Identifying where some of it sneaked into us and came along on our way out is often the hard part.