Boss: You know, you could be doing (something else) while you're waiting for (x).
Me: …
Boss: Time management (moves on…)
Me: (waits for him to leave then pulls out phone)
Yeah, except I don't actually care about that when I'm working. My job is a constant day-to-day type. I don't have daily deadlines of sorts, just occasional. Doing more work nets me no benefits. I don't catch up on projects, I come in 8-5 M-F and I work each day.
Of course, I don't tell him that as he's a boomer who still believes in hard work all the time. Great guy, usually, but needs to learn to relax.