I think this happens to every writer once in a while.
Today was building a family tree for one of my characters. Looked up some nice names fitting their ancestry, age and personalities.
Until I wrote down 'parents' Arthur
It took me just a little moment before it hit me... Arthur
I changed the name of the (grand)mother. I'm so happy I made character profiles and family trees before actualy introducing characters in my story.
Other writers here have a funny 'Oh... (*bleep*)' moment they want to share? (doesn't have to be just about names)