ability to focus or simply passion?

the last few days, my focus has been extremely high as i have been debugging some errors in a piece of software i need to get going to continue to press forward. i have made significant strides each day due to the ability to focus and concentrate for hours at a time. while taking a short break, i thought to myself, "is the focus that i have exhibited the last few days been because i am totally in love with my work or simply an exercising of an uncanny ability to block things out and focus for long periods of time?"

this was an interesting (and scary) thought to me because i was not sure what the answer is. i love challenges and solving difficult problems. i am very motivated to FINISH my phd and go to the next stage in life. i have always seemed to be able to focus intently for extended periods of time with no problem (prime example it studying for finals in college). and somewhere in there, i am very interested (not sure if love is the right word here....could this be my answer....lol?). my perspective may be a bit jaded because i have been working in this same area for such a long time that my true love for it is blurred and i perceive it as 'very interested' instead. just a thought.

p.s. - i listened to (but watched the majority of) the entire MJ memorial service today. it was very moving and very well put together.