Shocking? I think that's a strong word. I have, at times, forgotten about my other name, since I've had my current name for such a long time. I've had lenders/background checks, etc. come back with questions, and I just tell them I forgot.
I think it's kind of obvious because my original name was (for example, not my real name 😉): Stephanie Nicole Morris and my current name is Stephanie Morris Lawson... but perhaps it's not readily apparent.