Ask HN: Switched from Programmer to Product Manager - What can I expect?

One immediate thing that I've discovered is that I have much less control over the quality of my 'work'. As an engineer, I was always very confident as to the result of my code as I had total control over it. As a Product Manager, I've had to collaborate with multiple people from different departments with different agendas and ambitions, all working together shaping the idea (even in ways that I'm unsatisfied or uncomfortable with). The end product is usually different than my vision (for better or for worse), and as a result, I've been super nervous about the results of each project.

I know many readers on Hacker News have done both engineering and product management. What other things should I expect? How have you been able to secure the same level confidence as you did when you were an engineer? What tools and/or resources helped contribute to your successes as a Product Manager?