It will be hard to overcome a lot of gaps in education
- where is a phone (he seems to have signs "phone inside"), what kind of device am I even looking for, visually?
- is this operational? did someone forget this on the wall?
- how do you operate the dial?
- do you even remember a phone number that is useful now? When the smartphone suddenly stops working?
Sadly, I would probably score 2/4 and not rely on it.