They're taking the hobbits to Isengard

So why didn't Gandalf already know how to identify the One Ring? Isildur wrote down a first-hand account like 1000 years before The Hobbit, didn't he? And Gandalf clearly knew where to look it up because he went straight to it once it finallly fucking occurred to him that the ring might be important. And the identification process wasn't difficult, you just toss it in a fire and see if words appear.
What the fuck was he doing the entire time that the book was sitting on a shelf and his little tard buddy was running around with a galactic superweapon on his finger? Wasn't keeping track of shit like that his fucking job? Did he have better shit to do than learn the facts about the most powerful item in the universe?

>>212773573
He was being sued by Smaug's estate for aiding and abetting a burglary

TODAY IS MY WUNHUNDREDEDUHHLEDENT BIRTHDAY