Ghost or Imaginary Friend? Or Am I Just Crazy?

Here is one of those experiences I will be posting that may give off the impression that I might be crazy, but this really happened and still baffles my mind today (by the way, I hate that word "baffle" but it's the only word I could think of to fit there).

When I was younger, me and my mom used to go the the grocery store around the corner from us (Mad Grocer, anyone else remember this place?!) Anyway, I had to be about 4 years old or so because I don't remember a lot, but I do remember this man.  His name was Mr. Burns (I know you're thinking The Simpsons, but this was before the Simpsons was even made). He was a heavyset guy, probably in his late 60's, always wore suspenders, a light beard (gray in color), and most of the time wore a baseball hat.  He was always alone with his shopping basket, but was always friendly.  Seemed like he would only talk to me (maybe he preferred talking to kids over adults).

I remember him being there almost every time we went shopping.  He would always tell me to, "be a good girl for Mommy" and to always "stay with Mommy in the store". Sometimes when my mom would be going down another aisle, he would say, "you better go with Mommy, don't wanna lose her".
I also remember being in aisle where I was asking my mom if she could buy Tang (that delicious orange drink of the 80's) and she said yes, so I went over to get it and Mr. Burns stood there and said, "You like Tang, eh?" and I said, "yup!"

A few years ago, I remembered Mr. Burns and decided to ask my mom about him.  I told her the whole story and said, "You know, Mr. Burns, the guy at Mad Grocer" and she just looked at me like I was crazy! I said, "Come on, you know who I'm talking about!" and I described him and she was like, "Um, he might have been an imaginary friend or something because I have no idea who or what you're talking about". I even said, "You were there when he asked if I liked Tang!" and she was like, "you must have dreamt it or something.."  I asked her several more times on different occasions to see if she was just messing with me, but she swears she doesn't remember him or anyone like the guy I described.

Weird, huh?  I don't know what to think.. was he someone I imagined or was he a ghost that watched over me at the grocery store? Who knows, but I do know he was there.