What do you think about me having always wanted to be like the Joker?
Seriously? What do you admire about him?
The joker is the king of scum
Why would you aspire to be the "king of scum"? That doesn't sound very admirable.
Because he is pure evil!
You're not supposed to want to be "scum" or "evil". People are expected to strive for goodness and the Joker is anything but that.