@2184a19c My L1 is German and not English but imagine a situation where you as a new and aspiring superhero enter the scene. I would expect you to say: "IT'S ME –  NEVERFADINGWOODIO!". If you're at home watching telly with your family and footage of your totally awesome saving-the-day action comes up, then I would expect you to yell: "THAT'S ME - NEVERFADINGWOODIO!". No? 

 @3b40f373 Yes, except there is a vocal minority of speakers of British English that claims that only "It is I/That is I" is correct. Palpable nonsense, but there you go. 

 @2184a19c Oh I seee! I misunderstood your question... I thought you were talking about the difference between "It is ..." vs. "That is ..." and not the difference between "I" vs. "me" 🤦‍♂️ 

 @3b40f373 My fault. I should have been clearer. I was thinking out loud, so I forgot to give the proper context.