Lemonade Bankrobber

A person who is a stellar example of the Dunning-Kruger effect in action. That means they have very low experience in a subject yet greatly overestimate their skills, which more often than not makes themselves look like an ass.

It was named after the case of McArthur Wheeler, who was the inspiration of the Dunning-Kruger effect experiment. He robbed two banks after covering his face in lemon juice, believing that as lemon juice is used in invisible ink, that his face would not be seen on security camera footage and therefore he'd be completely anonymous and never be caught.

Don't be a Lemonade Bankrobber, "whom" is the objective case form of "who" and "thine" is the prevocalic form of "thy" Don't throw them around willy-nilly to look smarter. All you look like is a pretentious twat.