For years, rumors persisted that Bruce Lee did not show up on the first day of Enter the Dragon because he was having a nervous breakdown. But that's not true.
After the actor originally cast in a key role ended up injured on another production, Robert De Niro convinced Martin Scorsese to take the part himself.
Servant of the People ended up being the thing that actually launched Zelenskyy's political career, ultimately putting him in the position he's in now.
Alfred Hitchcock mistreated, traumatized, and forced himself upon his female co-stars, and that created quite a controversy with Tippi Hedren in The Birds.