The year was 1991. I had just wrapped up a less than sterling career as a computer programmer and systems analyst in the Insurance Industry. I could do the work, and do it well, but something seemed to be missing from my life.
As chance would have it, I ran across an MBTI tester from the Mind-Science Foundation in San Antonio, TX. After becoming friends with him, he surprised me one day by insisting that he give me the MBTI. Up until that time I had no knowledge of these kinds of test, nor that it would give me any knowledge about myself I didn't already possess.
He administered the test, and I came out INTJ (Introverted Intuitive Thinking Judging). Computer programming was a field I could do, but perhaps not the best field for me.
We modified my career plan to include research and then medical technical writing. I started my own business in 1993 and ran it successfully until I retired from it in 2006. The new career choice brought in the natural tendency of the INTJ to think in broad intuitive brushstrokes, and to make those all important cross-disciplinary leaps in thinking. I had several books published, as well as important articles.
I consider my experience with the MBTI the single best test I ever took, and recommend everyone take it seriously when it comes to careers.