Mikey (Sean Astin) from The Goonies (1985)
Mikey is younger than sibling Brand (Josh Brolin). He’s asthmatic, kind of dorky and prone to giving cheesy inspirational speeches (“Because it’s their time. Their time! Up there! Down here, it’s our time. It’s our time down here!”). But in the world of The Goonies, where kids armed with only a sense of childlike innocence can defeat armed robbers and real estate tycoons, Mikey is undeniably the star.
With the help of his friends, he ties Brand to a chair with his own exercise equipment, lets the air out of his bike (forcing him to ride a pink girl’s bike, leading to his humiliation in front of the girl he likes), leads him by the nose through a dangerous underground cavern and almost gets him killed.
And, to pour salt on the wound, Mikey ends up kissing Brand’s girlfriend before Brand does. It’s a good thing for Mikey that his older sibling is so well-adjusted, otherwise he’d have been locked in his room and noogie’d half to death long before meeting the Fratellis.