Not Fast Enough

I was just at the mall, walking from my car to the first store, and a woman walking toward me caught my attention. She looked a bit like me -- tall, dark jacket (vest?), wearing a hat... she looked a little familiar? Or she was staring at me? As we came near she said "You're Megan, aren't you?", to which I responded, idiotically, "Uh.. yes!".

"Nice to finally meet you", she said, before walking off.

I haven't the first clue who she is, and it all happened so far that my slow brain didn't catch up to turn around and watch her go before she'd turned a corner and was gone.

Hello, anonymous girl? Who are you?? Why do you know my name??