How long does it take to write the perfect query? Correction: How long can it take to write the perfect query?

I’ve been writing query letters since the 1980’s—longer than most of the agents I’m querying have been writing in cursive.
 
I’ve been revising the query for my current book for three years. Yes, it includes the requisite elements: gripping opening line, handle, platform, book length, details of my mad marketing skills, and why I’m the one-and-only-expert to write the book and you’re the one-and-only-agent to represent me.

If I seem jaded, I am. I picked it up from my grammar teacher in high school, who also taught me to experiment with punctuation in creative writing.  Jaded is a trait required of any person possessed to teach or study grammar in high school.

In 1995, I examined potential agents in New York for months before sending queries for a non-fiction book I co-authored with my husband, RJ. The book, titled Wrong Way, was an expose revolving around RJ before I knew him. (Ho hum, right?) I whipped out a query in one day. Two agents expressed interest in the book. One agent called. He was very excited about RJ’s story.
 
When Wrong Way was two-thirds complete, we moved to Missouri.  RJ announced writing the book was a cathartic experience and he no longer needed to tell his story. No amount of crying or cajoling (mine and our agents) convinced him to change his mind.  I watched a book deal slip out of my hands and learned two lessons: forget ghostwriting and best not to query our Wrong Way agent again.
   
Why has it taken me three years to write my current query for Have a Sick Day? Because, the former, straight forward query is a relic. Today’s query is a complex work of literary art with ever-evolving "required" elements. Today's query produces an endless supply of articles and books devoted to writing the perfect form of itself.
 
When I’m inches away from finishing off my quarry (I mean query), I spot another quarry (I mean query) article. I tell myself to ignore it, but my eyes are weak and dance across the text. If I follow the (mostly  repeated) advice, I could snag an agent.

Does agent lightening strike twice?
 
The form and definition of my quarry (I mean query) are morphing so quickly, I’m confident I’m chasing a shape shifter. Or else I’m crazy.

I am tilting a little sideways in my chair.