The first thing that an individual must thoroughly understand, is that geology is not an exact science. This may be strange for a geologist to say, but it is very similar to the profession of law in that any set of data may be and is usually interpreted differently by individual lawyers. We geologist start with some known facts (sometime geological), make assumptions, and then intrepret into the unknown. It is this interpretation that separates a successful geologist from a geologist. A successful oil finding geologist is a geologist that has developed this interpretation of geological facts into an art. It is this state of art that separates a successful oil finding geologist from a successful geologist.
Staggs, James O., "Geology for the Layman" (1981). Annual of the Arkansas Natural Resources Law Institute. 110.