The old boss who told me to stop chasing job titles

Back in 2017 my manager at a shipping warehouse in Dayton told me to stop applying for supervisor roles and instead learn the inventory software inside out. I thought he was just trying to keep me in a dead end spot, so I ignored him for 6 months. Then I got passed over twice for the same promotion because the other guy knew the system quirks. I finally took his advice, spent 3 weekends messing with the database filters, and built a simple report that saved our team about 10 hours a week. That got me noticed by the regional VP and landed me an analyst job I never thought possible. Ever had a boss give advice that sounded like a trap but was actually the best move?