The truth hurts
The story of Darth Plagueis the Wise isn’t something you’d hear from a Jedi. He was so powerful that his only fear in life was losing his power. Eventually, he was killed by the hands of the apprentice whom he had taught everything he knew about dark powers. His apprentice was none other than Sheev Palpatine, the guy telling Anakin his tragic story.
Even though the Jedi archives don’t contain Darth Plagueis The Wise’s story in great detail, it does mention something about his apprentice. Let’s just say that the archives don’t speak kindly of the apprentice in any way.