I wasn't really PIMO, but I can't imagine going to the weekly meetings (especially the midweek ones) and to field service for something I don't believe is real. I think that, on some level, I was already mentally gone before I consciously admitted it, and that made it easier to slowly drift away from the activities without really feeling guilty. There came a point where I felt like I had to drag myself to any JW activities and any excuse to stay home sounded good enough.
And that was when I thought I was still convinced it was the truth!