So, what's the takeaway? Seltzer is the friend who shows up in sweatpants. Club soda is the friend who brings a cheese board. Both are welcome.
And here's the best part: this is all just pretend science. Our taste buds are lazy. If you mix up the two, the universe won't explode. Probably.
Next time someone asks, "What's the difference?" you can grin and say, "Minerals, my friend. It's all about the minerals." Then take a dramatic sip. They'll think you're a genius. Or a water snob. Either way, you win.
Now go forth and bubble with confidence. Cheers.