It's not a story any Jedi will tell you. It's a Sith legend. Darth Sidious was a Dark Lord of the Sith. He was so powerful, he could create planet wide Force Storms with his mind, before crushing them with worm holes. He had such a knowledge of the Dark Side. He could even display such a genius in strategy, & tact, that he turned The Chosen One to the Dark Side, made him his apprentice while ruling over his hated foe nation & order covertly.
Naturally, the only thing that could stop him was his own extreme noob arrogance. Which of course it did. For while on his Death Star, the fit noob arrogance was so overwhelming, he forgot what a crafty genius he was, & about the bond shared between father & son that he had previously even warned that very father about.
His apprentice then snuck up on him, & threw him down a miles wide shaft.
Be wary young Sithlings, if you can't see your apprentice in your current line of sight, turn about, & short him out before returning to torture his son until he turns like you should have.....