Restricted phone calls....

I have a mystery happening to me lately, i have been getting at least one restricted phone call everyday...and i have no idea who it is...and obviously this is because it is restricted! One time they almost left a message i could hear the person start to breathe and then rustle around to hang up the phone. I don't know who it is, and i really have to make myself not answer the phone because i generally don't answer restricted phone calls, but i really really really want to know who it is! I have come up with a few theories...one is that it is a telemarketer, and thus it would not be cool for me to answer because they would take up my minutes! Two is that it is this real estate agent, i accidentally put in my real telephone number about a year ago to look for lofts and ever since he has called me incessantly, thankfully my number is an iowa number and so he thinks that i live in iowa...but it doesn't stop him from calling...my other theory is that it is someone i know who just likes messing with people, cause that is something i would totally do, i LOVE playing jokes on people and surprising them and what not...but i have to wonder, am i the only one who gets these phone calls? and if so....WHO IS CALLING ME?????