Something I wanted to tell someone about my kid's way of speaking

I won't say who, but there's something I felt like telling someone. You know how sometimes, even when you try to hold it in, you just can't help but let out a cough, burp, or fart, right? Every time that happened, I used to say 'Excuse me' as an apology. My younger child started imitating that and now, with a big smile, says 'Excuse me! 😁'. And today, what my younger child said after coughing really shocked me. 'I'm sorry for coughing 😄' Such a naturally polite apology. A preschooler skipping 'sorry' and going straight to 'I apologize'. When did they learn that? 😂 By the way, when I asked my older child, 'What do you say when you apologize?'… they replied, 'Sorry.' That's the normal way, right? 😅