I missed the part where that's my problem - You say this when someone brings up something you don’t care

You say this when someone brings up something you don’t care about and you’re not the one who has to deal with it.

'I missed the part where that's my problem' when my friend kept talking about her ex.

'I missed the part where that's my problem' after my neighbor yelled at me for my loud music.

'I missed the part where that's my problem' when my brother blamed me for his bad hair day.