insanity

I think it was Albert Einstein that best defined insanity. He said that insanity was doing the same thing over and over again and expecting different results.
Since I have gotten my Indiana cell phone I have received numerous calls for Dave. Some from people in Indiana, others in other states nearby. I don't mind it so much because that's life. Someone you know is bound to call your old number. Fine. I accept that. What I hate are the people that call numerous times, sometimes consecutively.

Me: "Hi, this is Dan."
Other: "Hi, is Dave there?"
Me: "No. This is Dan."
Other: "Oh, OK."
(dial tone)
(phone rings)
Me: "Hi, this is Dan."
Same person: "Hi, is Dave there?"
Me: (firmly) "No."
SP: "Oh OK."
(dial tone)
(phone rings again)
Me: "Look, you keep dialing the same number you're going to keep getting me."
SP: "Sorry."
(dial tone)

Once I even got a drunk girl asking for Dave to pick her ass up. When I explained that I was not Dave but in fact me, Dan, she asked me if I was sure. Then she asked if Dave was around, to which I replied no because you called Dan. She thought I was rude, which I was, but it was 4am and I had just fallen asleep from a night of drinking.
I'm sorry, but I've got a short fuse for the stupid. Is it possible to dial the same 7 or 10 digits and get someone else? Is there someone else out there that has the exact same phone number as me? Including area code? The phone company is just splitting up who gets which calls? Is Dave getting calls for me? Or is it possible these people that keep calling me are complete f***ing morons?
Pluralitas non est ponenda sine neccesitate or K I S S (Keep It Simple, Stupid). It is possible that two people could share the same phone number, although I'd like to believe that there are morons out there with basic phone skills (dialing) and no concept of what they're doing.
However, since I have taken the rude approach to answering these types of calls they have dropped to nil. Haven't gotten a call for Dave in a long time. Either I shocked them enough to stop calling or the phone company finally sorted out our calls.