The change doesn't come from thinking one is smarter or dumber, but you simply having much more information to work with. We form extensive opinions and views about the world relatively young, but it's largely based on things we have 0 personal knowledge or experience of.

Again I think the internet/social media are perfect examples. Predicting what would happen isn't about being smart or dumb. It's a matter of just not having enough real world experience to even begin to formulate meaningful views. And so the views and expectations we did form were quite out of touch with what really happened and indeed what we probably 'should' have expected to happen all along.