We all have one. The tool you dismissed, avoided, maybe even argued against — until one day you actually used it properly and couldn't imagine going back.
For a lot of people it's TypeScript. You thought it was just JavaScript with extra steps. Then a refactor caught a bug at compile time that would have taken hours to trace in production, and something clicked. For others it's Vim, or Docker, or Git itself back in the day.
What was yours? How long did you resist, and what finally made you give it a real shot?