Well, I have never known a Brendon, lots of Brandons, so if you pick an uncommon name, it is more likely to happen. And I speak as someone with an uncommon first name that people confuse with 3 more common first names.
Brandon is the 42nd most popular boys name of all time. Brendon isn't in the top 100. (mine isn't on the list either)
When I speak to my dear sweet 91 year old grandfather on the phone, he introduces himself to me as "your Uncle Ed." I actually find it sweet. He gets bonus points for remembering my name. I am one of 17 grandkids and 30+ great grandkids.
TV isn't on the list of top 100 names???
I think our family is a magnet for incorrect names. Ds is Braden so is always called Brandon. I always assumed Ava was a fairly simple name, but you would be surprised how many times she's been called Eva or even Ah-vah. A man at our old church called my dh Adam the whole time we lived there. His name is Patrick so I have no idea where that came from.