StbGuy

I've noticed many (not all) say "mother" instead of "my mother" or "father" instead of "my father" or "my dad".

Good point. For me however I cannot call them 'mum' or 'dad' because they are affectionate/warm/loving terms.
They were not loving they were self absorbed and cold. I do not hold them in high esteem or have any respect for them whatsoever.

"Anyone can be a father, but it takes someone special to be a dad, and that's why I call you dad, because you are so special to me. You taught me the game and you taught me how to play it right."
Wade Boggs

Now thats a dad!