Doorknob phenomenon

Doorknob phenomenon
"Everybody uses a doorknob at least once a day, but the only time they realize that they are using one of it is when it stops working"
This phenomenon occurs for almost everyone with many of the things in life including certain subtle tings like relationships, which they feel only when it is lost.
And coming to the ever increasing gadgets and plethora of other electronic devices. They might not make a mark in anyone's mind but they will certainly annoy everyone in their absence. Take the example of a smartphone. It is essentially a phone with extended functionality. But this may not be realized when one makes use of it but definitely misses the functionality a more when it is absent.