Does "I didn't know I could" mean "I didn't know I could be enlightened to break free of the vice of religion"?

Context:

If this book works as I intend, religious readers who open it will
be atheists when they put it down. What presumptuous optimism!
Of course, dyed-in-the-wool faith-heads are immune to argument,
their resistance built up over years of childhood indoctrination
using methods that took centuries to mature (whether by evolution
or design). Among the more effective immunological devices is a
dire warning to avoid even opening a book like this, which is surely
a work of Satan. But I believe there are plenty of open-minded
people out there: people whose childhood indoctrination was not
too insidious, or for other reasons didn't 'take', or whose native
intelligence is strong enough to overcome it. Such free spirits should
need only a little encouragement to break free of the vice of religion
altogether. At very least, I hope that nobody who reads this book
will be able to say, 'I didn't know I could.'