C172 MISUNDERSTANDS CTLR'S 'HOLD SHORT' CLRNC; TAXIES ON RWY AND CAUSED GAR.

Narrative

CONTACTED GND CTL FOR TAXI TO ACTIVE INSTRUCTIONS WITH WX AND CLOSED PATTERN. RECEIVED TAXI TO RWY 5. TAXIED TO RWY 5; COMPLETED RUN-UP CHKLIST. SWITCHED TO TWR AND ANNOUNCED READY TO TAKE OFF AT RWY 5. TWR REPLIED HOLD SHORT; I INTERPRETED INSTRUCTIONS AS TAXI INTO POS AND HOLD. A TRAINING 2 SEAT ACFT ON FINAL FOR RWY 5 EXECUTED A MISSED APCH AND WENT AROUND APPROX 200 FT ABOVE. TWR QUESTIONED ME ON UNDERSTANDING THEIR INSTRUCTIONS AND I REPLIED THAT I HAD INCORRECTLY INTERPED THEIR INSTRUCTIONS. I DID 6 TOUCH AND GOES WITH NO MORE PROBS. ON LNDG I WAS ASKED TO CALL THE TWR AND GIVE THEM MY NAME AND PLT'S LICENSE NUMBER. I HAD ARRIVED AT THE ARPT WITH THE DAY'S WORK STILL ON MY MIND. USUALLY FLYING HELPS TO PUT THE WORKDAY STRESS IN THE PAST. THIS TIME IT CAUSED ME TO INTERPRET THE CTLR'S INSTRUCTIONS INCORRECTLY. I SHOULD HAVE GONE HOME AFTER WORK AND GONE FLYING WHEN I HAD LESS STRESS FROM WORK. I HAVE HAD NO INCIDENTS IN THE PAST AND STARTED FLYING 35 YRS AGO. I WAS FORTUNATE THAT NOTHING HAPPENED TO ANYONE. I WILL NEVER FORGET THIS INCIDENT AND WILL BE 100% WITH THE AIRPLANE THE NEXT TIME I FLY.