Ever notice that some bottled water tastes like nothing at all, while other water has a taste you could actually describe? That difference almost always comes down to mineral content.
Heavily filtered and purified water strips out dissolved minerals along with everything else, which is part of why it tastes flat. Natural mineral water keeps what was already there. As water travels underground through rock formations, it picks up calcium, magnesium, potassium, and other minerals, and those minerals are what create flavor.
Crazy Water's taste comes directly from the specific mineral makeup of its source in Mineral Wells, Texas, different from mineral waters sourced elsewhere, and different across its own four numbered varieties depending on which well they're drawn from.
If you've never compared a naturally mineral-rich water side by side with purified water, it's a noticeable difference.