This is a personal story of a trivial mistake and its aftermath. I wanted a cellphone; actually, an Android phone that ran on a GSM network and, most importantly, was unlocked so I could buy prepaid SIM cards in any country I went to and use them in the phone. This was my desired solution to avoid the big roaming charges most carriers charge when you leave the country.
I had a trip to Mexico City and planned to do my shopping there. My colleague brought me to downtown, near Plaza Zocalo, and we found a raft of cellphone vendors. We picked one and started shopping. I told my colleague what I wanted, and he conducted the transaction in Spanish. They had a used phone for about $120. Android? yes. Did it work? Yes. Was it unlocked? Of course!
They demonstrated the phone by inserting a SIM card, messing around with the web browser and an app so I could be assured it worked. I was ready to buy. One more question: was it unlocked? Oh, yes!
I felt very happy with my purchase. I bought a SIM card in Mexico and the phone worked fine. And then, I brought my phone to the UK a month or so later, and... it didn't work. I tried several SIM cards and couldn't get the phone going. Where did you get this phone? I was asked. Mexico. OK, that explains it.
It was locked. After all that. I was thousands of miles from the guy who sold it to me. (As if I could even find him again.) As I pondered my mistake, I realized I could have made sure the phone was unlocked, at the shop in Zocalo, by simply asking them to test it with SIM cards from several different carriers.
But that couldn't help me with my current problem - which is that I have a cellphone that works great in Mexico, where I go a few times a year, but nowhere else.
There is a silver lining to this story, and that's what I wanted to share. I actually use the phone every day, just not for its intended purpose. I had been looking for a device other than my main phone that I could use to play music from the cloud. I considered buying a tablet, but eventually I realized I had the Mexico phone. Even if it couldn't connect to the cell network, it worked with wifi, so I could use it at home. It was Android, so it could access my music apps. A perfect solution.
So, the point is this, and I have learned this again and again. Very rarely is a mistake or failure a total loss. If you take the time to look for it, there is residue that you can use for other purposes, or take forward to your next project. When you buy a phone that ends up being locked, it's not so bad - you are instead the owner of a somewhat overpriced music player.