For me?
The shocking discovery that in 1985 my mother would choose to no longer even speak to me (because I had already long been faded - not DA or DF) simply because they told her to; researching Russell, and discovering the roots of the religion, his affiliation to the Masons (whether or not he was one is still not clear) but naming your Bible the "New World" Translation certainly indicates a very close affiliation; researching Rutherford and discovering what a drinker he was, that he authorized the purchase of Beth Sarim that he and his assistants would live in it complete with servants while the R&F were suffering during the depression; finding out about the 'Bethel Boys'; finding out about the JW's and the United Nations (that great old beast); reading Crisis of Conscience and learning that the GB rarely even prayed before making monumental decisions that affect every believer.
Thank God for the internet.