Let's assume that's the case. Then without having witnessed the propaganda, I'd not have proper context to what you just told me. I'd have to go with somebody (you) claiming what had been the propaganda back in the day. And that sounds pretty unbelievable, so it's good that I witnessed it, then I can appreciate the point that you are making.

Either way, better to have had open eyes and ears than not.

What's the tangible benefit of reading a history book? What's the tangible benefit of learning about quantum physics, evolution theory or the history of the French Revolution?

My iPhone works anyway, the grocery store sells chicken anyway, and the latte at Starbucks won't taste any different.

None of that directly changes by you learning more things. But it makes you a more well-rounded educated person, equipped to make better decisions impacting your own life and possibly society as a whole. And, frankly, to make sth out of you that's more than a monkey living merely to survive and procreate.