GA SMA HDG DEV WHILE ON A VECTOR HDG OUT OF MEM.

Narrative

THIS WAS THE LAST LEG OF A LONG FLT FROM COLUMBUS; OH; THAT STARTED AT XX30 PM THE DAY BEFORE. THE WHOLE TRIP HAD BEEN SPENT DODGING TSTMS. BEFORE DEP WE WERE CLRED FOR THE MEMPHIS 4 DEP THEN AS FILED WHICH WAS DIRECT TO WALET INTXN THEN V54 TO LIT; ETC; ENRTE TO DENTON; TX. AFTER TKOF WE WERE TOLD TO TURN TO HDG 270 AND MAINTAIN 5000 FT. AT ABOUT 4000 FT WE STARTED TO INTERCEPT OUR FILED RTE SO WE TURNED TO 225 DEG ON COURSE. DEP GAVE US TFC ADVISORIES AND I RPTED TFC IN SIGHT GOING R OVER US. DEP IMMEDIATELY GAVE US A VECTOR BACK TO 270 AND DIRECT LIT. THERE WAS NOTHING SAID AT THE TIME AND I NEVER FELT THERE WAS ANY DANGER BUT IN RETROSPECT I DON'T REMEMBER EVER ACTUALLY GETTING PERMISSION TO INTERCEPT OUR COURSE AND LEAVING VECTORS. THERE MAY NOT HAVE BEEN A DANGER THIS TIME; BUT I FEEL EASILY THERE COULD HAVE BEEN A CONFLICT IF A FEW THINGS WERE A LITTLE DIFFERENT. THERE ARE A FEW THINGS I FEEL MAY HAVE CAUSED THIS. FIRST; I FEEL FATIGUE AND STRESS PLAYED A MAJOR ROLE. AT THE TIME OF THE OCCURRENCE THE TRIP FROM OHIO WAS 10 HRS OLD AND HAD BEEN FILED WITH BAD WX. I FEEL MY THINKING ABILITY AND DECISION MAKING PROCESS WAS DULLED A LITTLE. SECOND; THE DEP DESCRIPTION IN THE MEMPHIS 4 DEP MAY BE A LITTLE CONFUSING AT EAST TO SOMEONE WHO SEES IT FOR THE FIRST TIME. IT STATES; 'CLRED AS FILED; CLB VIA RWY HDG OR AS ASSIGNED FOR VECTORS TO JOIN FILED RTE...'. I TOOK THAT AS GETTING VECTORS TO MY RTE WHERE I WOULD THEN TURN ONTO IT. NEXT TIME I WILL QUERY ATC.