Before we left New Zealand we purchased a first generation iPhone for my wife. It had a fair price of $100 New Zealand dollars but the process to get it working on a New Zealand network had stopped the WIFI component from working correctly. This was a pain as the data plans are quite steep and we had downgrade her account to a prepaid one for travel.
We soon learned that the iPhone had a temperamental battery and needed daily charging. International roaming stopped after we entered Laos and we left it off for a month or so. On returning to Thailand we found that the battery had started working again correctly. Imagine our surprise when turning the iPhone on here that the WIFI has returned from a lengthy absence.
There is a probably a scientific reason for the battery and WIFI learning to work again.
-I suspect the battery needed an extended off time to forget bad charging behavior.
-The changing of mobile networks multiple times seemed to reset the default WIFI settings.
A more abstract reason is,
-The battery needed to spend some time reconditioning itself in warmer temperatures
-The WIFI needed to scale numerous high Wats to increase its potency and remember its core function. Communicating on behalf of a higher being.