Have you noticed lately that every time you call a company: your insurance agent, your car loan company, your cable TV provider: the first thing they ask you for is your phone number?
I know why they do it -- it's a unique way to track customer records, and since most people won't give out their social security numbers to anyone who asks, and your phone number is more unique than, say, your shoe size, birth date or high school locker combination, it's a good substitute.
The problem is, that most of us have many phone numbers today. Each time a company asks for my phone number, I respond, "I don't know." It's not that I don't know my own phone number, but it's impossible for me to remember WHICH phone number the company might have on record. My home phone number? My cell phone number? My work number? My former home's phone number? My former cell phone number?
The upshot is, half the time I offer up my home phone number, the agent responds, "Hmmm...we don't seem to have that number on record." We end up trying several before my record pops up. And I find that as I get older, "former" numbers, such as that of an old cell phone, get a little harder to call up out of the biological memory bank.
Though oddly, I do remember my high school locker combination.