I’ve never seen 300. All I know is that there’s a Spartan king who sacrifices himself and his men for what they believe. Wikipedia says it’s loaded with historical inaccuracies (few movies are historically accurate). But whether 300 portrays history exactly as it happened is besides the point. 300 was so successful at the box office partly because it’s true mythologically.
We sacrifice for what we believe in. Constantly. Always. Period. You cannot escape this truth because even right now, you’re sacrificing your time (you can’t get it back, hence, sacrifice) because you believe that my writing is worth reading. (Thanks, by the way.)
What we believe to be true informs how we act. Time is what all of us place on the sacrificial altar of our conscious and unconscious habits. And yes, we could choose not to believe in this, that, or anything at all. There’s nobody stopping you from doing that. It’s entirely up to you to decide what you want to believe in. Just know that you’re free to choose what you believe. If you don’t like the consequences of what you believe, you’re free to change the ideas that inform how you act.
A wide variety of beliefs to pick and choose from — that’s freedom.