Are you by any chance an INTP? What you describe is a strong indicator for that personality type.
http://www.intp.org/intprofile.html
"The drive to understand things that are not yet understood is a very powerful force in the life of an INTP. Where the Ti preference is strong, this drive can override the experiential element so strongly that the INTP will become quickly bored with anything that he has successfully analysed to the point of understanding it. Once understood, it has nothing left to offer, once the satisfaction which comes with achieving the goal of understanding diminishes."