a little sneak sneak
When someone does something so sneaky and tiny that it's like they took one step and now they're telling the whole world they're the next Einstein.
My brother did a 1-yard sneak and now he's saying he's the best quarterback in the world.
My sister took one bite of cake and now she's saying she's the queen of the dessert world.
My dad took one sip of coffee and now he's claiming he's the best coffee drinker ever.