Me, 14 years into my career, all the freakin' time at work: "So I have no idea what that means. Could you explain it and/or show me where I can learn more? Thanks!"
I love seeing other managers and leaders do this too. While I believe it's important for me to know my work/field well, it's also important for me to know what I need to know, ask when I don't know, trust in the expertise of others when needed, and make sound/informed decisions whenever possible.