The old view is that curiosity and boredom are opposite ends of the same continuum.
The new view: bored is not to curious as hungry is to full or thirsty is slaked. Rather, boredom is a signal that you’re not making good use of a part of the brain. And there are antidotes to boredom besides curiosity.

Boredom alone can’t fully explain curiosity

From an evolutionary perspective, there’s good reason to keep looking, to be curious. 
Information helps us make better choices and adapt to a changing environment.

Curiosity and evolution

Curiosity doesn’t seem to be tied to any specific reward.
It makes sense for organisms to seek food, water, sex, shelter, rest, wealth, or any of the other myriad nourishing and pleasant things in life. But what is the good of deducing the nature of gravity, or of going to the moon?
A simple answer is that we never know if what we learn today might come in handy tomorrow.

The paradox of curiosity

In a 1994 paper, George Loewenstein theorized that curiosity’s direction is determined by the “information gap,” the sudden awareness of what you don’t know and the immediate desire to fill that gap.
But for the information gap to set its hook, though, it can’t be too big or too small - Curiosity peaks when subjects have a good guess about the answers, but aren’t quite sure.

The information gap

Scientists who study the mechanics of curiosity are finding that it is, at its core, a kind of probability algorithm—our brain’s continuous calculation of which path or action is likely to gain us the most knowledge in the least amount of time. Like the links on a Wikipedia page, curiosity builds upon itself, every question leading to the next. And as with a journey down the Wikipedia wormhole, where you start dictates where you might end up.
Curiosity is less about what you don’t know than about what you already do.

Curiosity as a probability algorithm

Humans have a drive to eat. We have a drive to drink. We have a drive to reproduce. Curiosity is no different, says George Loewenstein, a professor of economics and psychology at Carnegie Mellon University. Our insatiable drive to learn-to invent, explore, and study ceaselessly-"deserves to have the same status as those other drives."