This has been part of a larger life exercise in practicing general moment-to-moment mindfullness, and I think I'm going to keep this up for a while and see how long I can go without a smartphone before people start asking me questions at work. So far, so good.
It's like I've withdrawn from a drug and some of my attention is back under my control, where my mind can better keep its peace. I guess I didn't exercise proper discipline when I had the phone.