And since "important" is relative to the person making the sacrifice, it's easy for a person to declare something a sacrifice when what they were giving up was not especially important to them, or on the other hand for someone to dismiss a "real sacrifice" that someone else has made as unimportant.
Not that this matters, really. But I think it's important not to use them synonymously. In the case of an opportunity cost, you are acknowledging that there were things given up. In the case of a sacrifice, you are saying there were things given up _and it hurt_.
denotation and connotation. They have the same literal meaning (denotation) but certainly not the same implication and tone (connotation). Choosing to eat a turkey sandwich vs roast beef is an opportunity cost. I'm forgoing the roast beef. But it isn't really a sacrifice. I could say that it, and it would be true in some sense (denotation) but it would be very hyperbolic of me.
What if top-tier "greats" viewed every 'sacrifice' as superficially as roast beef vs. turkey? Even the ones we decidedly do not, like having a kid, starting a family, etc. vs. what they want to do?
