I strangely acquired this habit at home shortly after my first son was born for some conversations...

"I need to do this now" became "Daddy needs to do this now"... It is weird, and entirely unnecessary, kids acquire understanding of "I" and "you" quite fast. It just came and never went. I think I was trying to be less ambiguous when conversations did not involve only me and the kids, but also Mum and others, or when I somehow want to emphasize the context and my role (?) I have no idea and it is fading, only a lot of company present might trigger it - or recounting stories to others.

But maybe I just never realized how weird it is - I would raise both eyebrows if a colleague at work would talk like that in a "normal" context.