I am not what you would call a heavy cell phone user. I probably use it once per day to check in with the wife about something and maybe call someone to make or break and appointment. I use less than 100 minutes per month, usually. But I do use it for other things, like keeping contact information, keeping time, and for "emergency purposes".
The first day and a half I felt naked and exposed. What if someone is trying to call me? What if I need to contact someone? Keep in mind that I have a land line in my home and a phone on my desk at work. These devices have existed for decades upon decades and subconsciously I forgot about them.
By the end of the second day, I was less anxious. I couldn't immediately contact my kids but they are in a school (that has phones!) so if there was an emergency, there is only one place they could be.
I use my cell phone also to store phone numbers and as my wake-up alarm. By the third day, I realized that I probably didn't need 80% of the numbers I had there and the few that I did I could probably memorize (use my brain? what?). I pulled an old, dusty digital alarm clock out of the closet and used it for the first time in five years. I also use my cell phone because I don't wear a watch. My wrists are small and I always break the bands because I pull them too tight. After a while I realized that except for getting up in the morning, the time doesn't really matter much.
On the fourth day, I stopped thinking about it completely. I didn't inadvertently reach for it as I had done for the first two or three days. I had to arrange things in advance in the morning since I could not text people on the fly. I told people when and where I would be and at what times. Any time that was outside of that range, I would be unreachable. Period.
I found my phone this morning. The battery is dead. I will not be able to charge it until tonight. I don't care what voice mail messages were left for me. I have no urgent need to text message anyone.