Making the decision to dive headlong into Scientology and become a contracted staff member was one of the most catastrophically expensive decisions I've ever made in my life. I've often wondered "what was I thinking??" when I made that decision and "how can I possibly improve my understanding of decision making to help guard against making decisions like that ever again"?
I found a course online that I've recently purchased and started on that is fascinating for anyone who's ever asked the same thing of themselves.
There is a really great website at www.teach12.com which sells DVDs, audio CDs, and course packs of selected university level courses, mostly on science and the humanities.
I recently started a course I purchased from there on Critical Decision Making, taught by professor Michael Roberto of Bryant University. I'm only 2 lessons of 24 into it, but already it has really shoved my pre-Scientology and Scientology decision making processes straight into my own face and forced me to look at things in new ways.
I'm learning about certain kinds of cognitive biases and other influences that shape the decision making process which were heavily at work in me when I decided to become a Scientologist.
It's really great.
If you are interested, click around on that link above. This is my second course from there, and both courses for me have proven very worthwhile.