There are some, like:
Find a shiny when you are actually searching for it
Click the A button infront of a tree that can be cut without any of your Pokémon knowing the move cut
Run without running shoes
Ride your bike inside of a room
And when Pokémon first came out - to get to the grass on the sides of Pallet town to find Pikablu
Yeah, good luck with it...
And so many other hillarious things...
Say what you always try in Pokémon games even though you know it's impossible...