Though I didn't learn TTATT by myself -- I have JWfacts to thank for showing me the information that really showed it couldn't be the truth -- I did have an epiphany a year before that, which, looking back, must have been when I first "awakened". I had come across a new word. It's always a major event in my life when I see an unfamiliar word because I am a language fanatic. I saw someone describing his religion as "Jesusism"; I just had to look that word up. Sure enough, as one would logically guess, it means "following the teachings of Jesus only, not any additional writings by Paul or other later religious leaders".
Suddenly it struck me: it was entirely possible for me to live an upright life without the religion's imposed morality, by just following Jesus' words, and what's more, this meant that the organization was the modern-day Pharisee class! They had added a bunch of oral laws onto the original, simple teachings. It was all so clear that they were burdening their followers unnecessarily. I immediately felt a huge load lifted from my shoulders.
I didn't yet know any good arguments against Watchtower doctrines, nor did I realize for a while longer that "Jesus' sayings" are difficult to attribute reliably to Jesus, and many of his sayings probably were inserted retroactively by later Christians or came from earlier rabbinical sources. But just looking up the word "Jesusist", and learning of a concept that I didn't have any clue existed before then, was a huge step in seeing a difference between the words of the Society and the word of God.