You have it the wrong way round: when you're young, you (want to) believe your actions have world-changing impact and reach. Then you grow up, and see that the world is much bigger than you, bigger than your ego even, and cannot be wielded or moulded by anyone; so you learn to focus on what's around you and who's around you.
I actually do agree with you.
If you "think locally and act locally" while young, you run the risk of being blindsided by tail outcomes in the future.
I think either global thinking or acting in youth is a prerequisite to arriving at the position you describe. I mean, is there a better explanation for mid-life crises?