For me it feels like grieving the loss of something familiar, reflecting the communications I have with the people in my life. In modern life it seems like the device is the "memory" of it rather than my head or heart.

I also have a hard time letting go of devices, particularly laptops-- critical for my work travel-- because I can trust it to do what I need it to do, so it's like letting go of certainty too. A new laptop will probably work (and each one does kind of work better) but my fear is what if?