Hello! It may be that you misheard something because in natural English when we speak about "I" we use first person narrative which means that the person speaking is speaking about themselves. For example; “I’ve never been to this restaurant." But if you are speaking about "him/her/he/she" then it is the third person narrative which means that you are talking to someone (second person) about someone else (third person). I'm not a hundred percent sure about the context of the sentence but perhaps it should be written like this: I’ve never been to this restaurant "with her" cause she was in her workplace. - in this sentence the person is speaking about themselves (first person) but also about someone else (third person). Perhaps you could explain the context a little more... I hope that helps!

Nope, we never do that. Sometimes people refer to themselves by their own name but this is considered annoying by almost everyone. Here is a YouTube clip of a guy named Jimmy refering to himself by his own name from a popular television programme called Seinfeld. https://www.youtube.com/watch?v=Apa0nG1OfUc If you are going to refer to yourself by name then you need to use the he/she (third person singular) verb conjugation. Seriously though, don't refer to yourself by your name; it's irksome.

it is a flamboyant style of speaking

@Mr.Michael Thank you for your commitment. I appreciate it.

People do sometimes do this - speak about themselves in the third person - but it's not really something to copy. And I'm afraid I can't make sense of your example. It may have been misheard, or just misspoken - sometimes our mouths say things not quite as we intended. https://melmagazine.com/en-us/story/the-psychology-of-referring-to-yourself-in-the-third-person https://counsellingresource.com/features/2016/02/01/illeism-and-narcissism/