I hate making mistakes. I am a perfectionist at heart.
However, when you do complex work, the more you try to prevent mistakes, the more mistakes you'll actually make. Nothing you do will prevent getting some things wrong the first time around.
You're limited by what I call the fog of beforehand: what you can know before starting the work. In a complex domain, we know that isn't good enough.
We often worry about underplanning, but overplanning is as dangerous. Overfitting your plans means you're making plans grounded in noise instead of signal.
Too much planning and instructions is an anchor that stifles the ability to respond and incorporate new learnings. That anchor creates a false sense of security and actually slows you down when you have to change course.
Acting based on what you know isn't good enough. You have to incorporate what you discover and learn. Adaptation is necessary and essential, and cannot be prevented no matter how long we sit in meeting rooms.
Don't worry about getting your plans wrong - you will. Worry about how quickly you can make changes based on what you discover and learn.
Remember, it's called Agile and not Steady.