Goldilocks

Apparently from goldilocks, equivalent to goldy +‎ locks (“tuf of hair, curl”).

Goldilocks

1. The protagonist of a traditional fairy tale. She is a golden-haired young girl who inquisitively enters the house of three bears and tries their three bowls of porridge, three chairs, and three beds, in each case finding only one that suits her.
2. (used attributively) Something in a happy medium or optimal point between two extremes.
   • 2002, Gary Cokins, Activity-Based Cost Management: An Executive's Guide, John Wiley & Sons →ISBN, page 87

     Once the appropriate levels are stabilized at a Goldilocks level, not too detailed nor too summarized, then the connection of the ABC/M data to business problems, their analysis, and ultimate solutions can follow.

   • 2013, Peter Collier, A Most Incomprehensible Thing: Notes Towards a Very Gentle Introduction to the Mathematics of Relativity, Incomprehensible Books →ISBN, page 14

     The mathematically rigorous texts, on the other hand, are unreadable for the non- specialist. I was looking for something in-between, a Goldilocks volume pitched just at my level, neither too easy nor too difficult.

   • 2014, Laura Stapleton, The Very Best Man, Stapleton Enterprises →ISBN

     He sighed at the Goldilocks temperature. Jane might think different, but this felt perfect to him.