How do I focus on what I can control at work and let go of the rest?

This is the first and most freeing idea in Stoic thinking: some things are up to you, and some aren't. Up to you: your choices, your effort, how you act. Not up to you: outcomes, other people's decisions, the market, the reorg, what others think. Almost all stress at work comes from grabbing at that second list as if you controlled it. The practice is simple to say and takes a lifetime to live: put yourself fully into what's yours, and let the rest go — not by giving up, but because spending energy where you have no power is just waste. You control the quality of your proposal, not whether it's approved. You control how you show up to a hard talk, not how the other person takes it. Draw that line honestly and two things happen. Your effort lands where it can actually move something, so you get more done. And your peace stops depending on results you were never holding. That's not checking out. It's what lets you care about the work without being ruled by it.