I think "influencing/leading people who do not report to you" is one of the hardest, most underrated part of mid-level people's jobs. When you're a low-level Individual Contributor, it's easy: You're not expected to lead anything or influence people. Take your ticket, do a great job at it, then take the next ticket. You're given a task, design it, and implement it, and job well done. On the opposite end, if you're a director or senior manager with a big org of people who report to you, it's also easy (or seems easy from my vantage point): You simply say "we must do this thing" and people do it. In the middle, we don't have direct reports, and nobody has to listen to us, yet our job is to convince people to do the right thing. Very difficult. You need to be political, cognizant of perception as you say, you need to gather favors and then call them in, prioritize and horse trade for things that are important, and so on. Difficult job.
