A couple of months ago, my wife and I changed our cell phone numbers. This was good because it gave me a chance to have our cell phone numbers reflect our new location. My old number was from Lansing, where I used to work, but never lived. The new one is much closer to where I live and work. The old number also managed to accumulate all manner of people I no longer wanted to talk to. They now get a disconnected message. Good riddance!
The bad news is that the cell phone company reassigned my number so quickly that the friends of the previous recipient didn't even notice that the ownership had changed. Consequently, I've been getting several calls a day for Earl. I answer them politely and tell them that this is no longer Earl's number and that I unfortunately don't know his new one. Lots of them respond with "Are you pulling my leg? You sound just like Earl!" Nope, sorry, my name is not Earl.
I also know that this could go on for years. When I moved to Ann Arbor 21 years ago, my number was the old Alcoholics Anonymous/Alano Club number. I got calls for AA for nine years.* At one time, I had the new number memorized so the callers could find help. My dad was a member of AA, so I know how how important these calls were.
ETA: This happened to me again when I moved out to Irish Hills. My number was the old number for Jerry's Pub, which was also my hangout. I didn't get nearly as many phone calls for them as for Alcoholics Anonymous in Ann Arbor (heh, AA in A2), but I did get enough that I memorized Jerry's number to tell them where to call. When I told the daughter of the owner about the situation, she was appropriately amused.
*I once took advantage of this mixup, but that's a subject for a future friends-locked post.