Out of all the possible questions such as:
How does getting sucked down a drain put you in a different world?
How do you get sucked down a drain in the first place?
How is Mario able to jump like 6 times his height?
Why does he grow to twice his size when he gets a mushroom actually bigger than he his?
What is Mario actually doing with the mushroom anyway?
Why does Mario jump the same height with able becoming giant-sized?
Why does he fight evil walking mushrooms called "Goombas?"
...
Why ask about King Koopa?