I taught fifth grade full-time in the Los Angeles Unified School District. At night, I went to graduate school full-time. I was a teacher by day and a student by night.

In March 2003, I earned my master’s degree in information technology with a 4.0 GPA. I was proud of it. I also knew how much I hadn’t seen yet. My road to mastery began after graduation, when I had to put what I’d learned to work on problems that didn’t come with an answer key.

In Outliers: The Story of Success, Malcolm Gladwell popularized the idea of 10,000 hours. I’ve put in well over 10,000 hours learning and working in technology. I couldn’t tell you when I crossed that mark. What I can tell you is when I noticed what those years had given me.

I was preparing for a recent interview and going through old project notes. I asked myself what I’d missed at the time and what I’d do differently now. One lesson kept coming back: when teams bring you competing requests, find out what each team is trying to solve. Sometimes two requests that sound different are really about the same problem.

When the interviewers asked how I’d handle competing priorities, I paused and asked how requests reached them in the first place. Their answer gave me a better starting point than anything I could have rehearsed. I’d spent the week preparing for the interview, but I’d spent years learning to ask that question.

I’m comfortable now calling myself a leader, a mentor, and an advisor. I’m also more comfortable with the word master than I was when I earned the degree. In a field that keeps changing, mastery means knowing when to trust your judgment, when to ask another question, and how to help someone else develop judgment of their own.

I started out as a teacher by day and a student by night. I still get to be both.

Your turn: What’s one lesson it took you years to learn? Share it with someone who’s just getting started.