Because you like Charles Foster Kane in Citizen Kane
Rupert Giles is a librarian on the outside, fearless evil-fighter on the inside. See them in Buffy the Vampire Slayer.
Greg Heffley will be famous someday, but now he's stuck in class with morons. See them in Diary of a Wimpy Kid.
Alex Danvers is a brilliant engineer tasked with alien threats, and one of those aliens is her adopted sister Supergirl. See them in Supergirl.
A believer in the pursuit of justice, Garrus Vakarian hates it when bad guys slip through the cracks of the bureaucratic justice system. See them in Mass Effect.
Foggy Nelson is a principled small-time lawyer fighting for fellow little guys. See them in Marvel Cinematic Universe.
Relentlessly cheery Ned Flanders enjoys a nice piece of bread with water on the side for dipping See them in The Simpsons.
From secret organizations to alien attacks, Kyon's life has been one weird, unexplainable thing happening after another. See them in The Melancholy of Haruhi Suzumiya.
Tony Montana makes up for his language barrier with his immense skill at cursing as loud and effectively as humanly possible. See them in Scarface.
This power-hungry Time Lord calls himself the "master of all." Bonus: he has 13 lives. See them in Doctor Who.
Marge Gunderson embodies the very best of the American Midwest. She's kind, friendly, and fiercely honest. See them in Fargo.
Charismatic, sociopathic, and dramatic, Charlie Bronson wants nothing more than to be famous. See them in Bronson.
Benoit Blanc is Sherlock with Southern charm, and a mysterious benefactor. See them in Knives Out.