I was leading a retrospective with a client team today, and one of the developers suggested a change to a process that I'd put into place; a process that I've used successfully with other teams for years. The change he suggested was absolutely the right call, and I'll be incorporating it into my work with future teams.
But when he suggested it--for just a split second--I had to check my ego. "But you're the expert", my ego said to me in the moment. "Surely this relatively junior developer doesn't have better ideas than you."
Of course his ideas have at least as much merit as mine. Much of my expertise is hard-won from a decade as an individual contributor, technical lead, and manager. But I haven't made my living writing code in several years. This developer is steeped in the processes that I'm shepherding, and like any intelligent human who enjoys solving problems (ie. developer) he is going to have ideas for improving the things that surround him. And he's certainly going to see things that I don't.
If you want to see as much as possible, make sure you're using all of the eyes that are available to you.