When someone feels entitled to knock hard on your door, they think you are obligated to them in some way. It is a very disrespectful power-move. People who respect you, are scared of you, or owe you something wont knock hard on your door; they will text and say, "I'm here. :)"
"You think I am in danger? No, I am the danger. You think when someone opens their door and gets shot, it'd be me? No, I am the one who knocks" -Breaking Bad
"It's a hard knock life for us" -Orphan Annie & Jay-Z
Referring to the habitual status of your mask wearing hygiene.
Friend 1: Hope youâve been wearing your mask
Friend 2: how nice, are you concerned about my maskedness?