Day 18 - Focus or Obsession?

I have really been hunkering down and focusing on Goal 1 the past week or so.  I've started my GMAT class and have been trying very hard to do a little each day.  I just completed my 3rd class session and am feeling pretty good. 

In order to be focused and orderly about pursuing my goal I have been trying to follow some basic Zen rules.  Not multi-tasking, not having Goal ADD and setting specific milestones.  So far I have incorporated some studying into each day, scheduled my "Ultimate Practice Test," scheduled my actual test date (this gave me a minor anxiety attack), took off some days from work just prior to the test and prioritized my study schedule.  Focused?  Yep.  Check.

But when does it start to cross the line from being very focused to being borderline obsessed?  I mention this because I think I've been displaying some "obsessed" symptoms over the past couple of days.  Case in point:

• I brought my course book to work and actually photocopied an entire practice set.
• Further - I then worked on this practice set whenever I had "free time" at work (aka my lunch hour or while I waited for a database pull)
• I choose studying over dinner
• I have started reading my pocket reference book on the bus rather than my very interesting "leisure" book
• I've totally stopped running and removed myself from running commitments - I sold my race ticket to my friend Steve today
• I've been contemplating "How much sleep do I really need?" 

Is the GMAT taking over my life?  I actually woke up last night at 4am feeling sort of awake and I thought "maybe I should do a practice set?"  

Hmmm.

So I'm at the point of asking - am I focusing or am I obsessing?  Is there a difference?