How would you go on Parent/Teacher Conference? Show/Tell? Will your kid say "My mom/dad is a floating head!"
On dates, will you just bring their head if the body is sick due to fever?
Well... technically speaking, if they are your biological parent then they would have to be a headless body, not a floating head.
For the record, a Duliahan in traditional lore referred to the body and they carried their head under their arm.
EDIT: (If you want to go to the REALLY traditional lore, Dullahans have an immense aversion to being watched, and will physically assault anyone who looks at them. In a good case, they will throw a vat of chicken blood at you. In a bad case, they will gouge your eyes out with a whip made from a human spine.)