PIPER PA31 CARGO PLT MISTAKENLY FOLLOWED TAXI RTE HE KNEW OF INSTEAD OF FOLLOWING GND CTLR'S CLRNC.

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AT APPROX XA15 I RECEIVED MY CLRNC TO TAXI TO RWY 29L FROM FAT GND. THIS IS THE USUAL CLRNC AND I PROCEEDED TO TAXI TO RWY 29L. 1/2 WAY DOWN TXWY B; GND CALLED AND SAID TO TAXI TO RWY 29R TO AVOID A LONGER WAKE TURB HOLD FROM A DEPARTING B757. I READ BACK THE NEW CLRNC TO RWY 29R. THIS IS WHERE THE PROB STARTED. FROM THE NUMEROUS TIMES THAT I'VE FLOWN OUT OF FAT; THE FEW OCCASIONS THAT I HAVE TAKEN OFF FROM RWY 29R HAVE ALWAYS BEEN AT INTXN B2. FOR SOME REASON; IT WAS IN MY MIND THAT RWY 29R STARTED AT TXWY B2. SO MY UNDERSTANDING OF THE NEW CLRNC WAS A CLRNC TO TAXI ACROSS ALL TXWYS AND RWYS AND HOLD SHORT RWY 29R. I PROCEEDED TO TAXI ON TXWY B; TURNED L ONTO TXWY B2; CROSSED RWY 29L AND HELD SHORT OF RWY 29R. AT THIS TIME GND CALLED AND INFORMED ME OF MY 'POSSIBLE PLTDEV.' FACTORS: BECAUSE I THOUGHT I WAS FAMILIAR WITH FAT; I DID NOT HAVE MY ARPT CHART OUT. AFTER GND INFORMED ME OF MY DEV; IT ONLY TOOK 1 QUICK LOOK AT THE ARPT DIAGRAM TO SEE WHERE I WENT WRONG. MY HOME BASE IS ZZZ. THEY ALSO HAVE PARALLEL RWYS; BUT THEIR THRESHOLDS START AT THE SAME POINT. YOU HAVE TO CROSS ONE RWY TO TAKE OFF ON THE OTHER. THIS MIGHT HAVE PUT ME IN THE MIND SET THAT I HAD TO CROSS RWY 29L TO GET TO RWY 29R AT FAT. AT THE TIME FAT GND GAVE ME THE NEW CLRNC TO TAXI TO RWY 29R; I WAS DOING MY WT AND BAL AND MY BEFORE TKOF CHKLIST. I DIDN'T PUT AS MUCH THINKING INTO THE NEW CLRNC AS I SHOULD HAVE. IF GND CTL HAD SAID 'CONTINUE ON TXWY B TO RWY 29R;' THAT MIGHT HAVE CLICKED SOMETHING IN MY BRAIN REGARDING HOW TO GET TO RWY 29R. HOWEVER; I DON'T THINK THEY COULD HAVE FORESEEN WHAT I DID FROM THE SIMPLE INSTRUCTION 'TAXI TO RWY 29R.' IRONICALLY; I HAD JUST READ A 3-STEP PROGRAM TO PREVENT RWY INCURSIONS THE DAY BEFORE THIS OCCURRENCE: 1) HAVE ARPT DIAGRAM OUT; 2) LOOK AT THE ROUTING; 3) WHEN IN DOUBT -- ASK. THIS COULD HAVE BEEN AVOIDED HAD I DONE ANY ONE OF THE PREVIOUS.