Tigger and Central Idea-Promise to the Reader or not

I was driving home yesterday thinking about how students sometimes have trouble figuring out a central idea in their expository writing.  They tell you lots of reasons why but no central idea. So then I, for some reason, thought about Tigger and how he tells us lots of great things about Tigger and then states, "but the most wonderful thing about Tiggers is I am the only one!"  So, then I thought about maybe analyzing Tigger's rant about himself.  At the same time thinking of revising it for a central idea. I know it's descriptive and such but you could make it why does Tigger love himself or why do you like Tigger.  It depends on the purpose.  Since I am thinking about it from an explanatory vain, I'd have to tweak it in an explanatory way. Just something to consider. 
  You could even take it to so far as to put in STAAR format and add a Revision question like-which sentence best states the central idea to Tigger's composition or something like that. I need to check my sample items.  But the students and teacher could discuss what they think Tigger's overall main or central idea is and then use that as the sentence.  I would have to write it all down and will soon.  Just thought it would be fun!  This came out of my time at BHE yesterday.  I worked with a wonderful, fun and energetic group of 4th grade teachers.  We were discussing some student writing samples along with the STAAR Rubric.  We had a great discussion with the central idea.  Let me know what you think by commenting below.