A protagonist who knows little about the world he born and grew up in until majority (present)?

Question

This protagonist born and lives in a peasant village in a medieval-like age, where education and science aren't known much. But a certain awful event occurs in this village that leads this character to leave his homeland and starts a journey to put an end to the causer of such event.

But many things about the world are unknown by him, and have to be explained by another character that knows about them.

My question is: is it believable that the protagonist only know about things related to his village and peasant life, and nothing more? Or would he look too "ignorant"?

Answer 1

This is a classic "cabbagehead character," who allows you to gradually unveil your worldbuilding as he leaves his isolation and goes out into the larger community.

Nothing wrong with this at all. First example I can think of is Garion from David and Leigh Eddings' pentology The Belgariad (and second pentology The Malloreon). He is exactly what you describe: a sheltered peasant boy who leaves his small village to venture out on a great quest. In fact, one of his adult companions, the smith Durnik, is also a village man (a blacksmith, so not utterly ignorant) who joins the adventurers and learns about the larger world.

Very usable trope. Go for it.

Answer 2

It's understandable that your character doesn't know many things about the world when he leaves his village. That's where he came from after all.

But he should know "a lot more" by the end of the story. That's just part of his "journey."

If he doesn't, that's when he would look "ignorant," not having learned anything (or at least "enough") from his experiences.