Whodunit

Where do I start with a dilemma like this? Go to the police? They'd lock me up. Psychiatrist, you say? Well, all I can say is that in every other way, I'm as normal as the next resident of the 21st century - no unusual tics, get along well with my fellow man, no delusions, unless you want to count this one. I may be no judge, but everything is normal except for this, and it's as real as my hand in front of me.

It seems logical, accepting that this is real, to try to make an observation about the people who've given me the message (or asked me the question, as the case may be.) Are there any common denominators there? Believe me, I've wracked my brain - nothing. But just so you can go through the same exercise, here's the list:

A young man who sidled up to me on a city sidewalk on his skateboard - he was the first.
A well-dressed gentleman, looked like he had just come from work, approached me in the aisle of a supermarket.
A young woman, I'd describe her as nondescript in every way, thirtyish, approached me in a department store.

Get the picture, or should I go on? I've never been approached by the same person twice, and none of these individuals gave me any hint as to who he or she was. I've considered scouring the want ads in the local papers to see if someone is possibly being paid to do this. I think that would be a good first step, and one that makes sense.