You recently got drunk, resulting in you buying something stuiped, and stuipedly cheap at that, product. it was a Giant Battery with a giant Warning of "Do not let any Electric-type Pokémon touch this.", you shrug it off as a decoration for a bit until your normal Pikachu approaches it in the back yard.

"Hey master! can I touch the giant weird Battery in our yard?"

you had no idea what it would do, but you were still recovering from the hangover.