Alana, while drinking water over soda or other drinks that have caloric content is vital, I'm going to argue with the amounts you have listed. If you read the entire article you are referencing on WebMD, (http://www.webmd.com/a-to-z-guides/features/wonders-of-water) there are at least two locations that say basically the same thing. The most entertaining is this one:

As you'll notice, at the beginning of my post the quote states beverages (so all things liquid count towards your "water" intake). I just didn't feel the need to put water/beverages/liquids and keep it simple to just water... If everyone read the small quotation they'd understand that it applies to all beverages. Although, since we are trying to instill healthier habits into our lifestyles anything that is low in sugar and sodium would probably be best. Not only because its better for our bodies, but because it's lower in calories as well. All those "extra" numbers in macros that we are "saving" can be used for foods to keep our bodies nourished instead of liquid calories that aren't filling.

Oh, and you are right... Cavemen did not go around with water bottles... But they were DEF more in tune with their body signals... A thing that some of us may have slightly lost (although not completely)... Here is an article, which also recommends the amount I listed previously, and also lists some possibly important questions that may helps us in asking ourselves so that we may be able to better determine if we are hungry or thirsty: http://dcp.psc.gov/ccbulletin/articles/FitforDuty_050607.htm . Here's another article, that although is on the PKD website (which is geared toward individuals with Kidney Disease): http://pkdhealthnotes.org/q-and-a/hungry-or-thirsty/ . The dietician that wrote the article lists the symptoms of hunger and the symptoms of thirst, which also may be helpful for some of us to determine the difference.

I hope you find these helpful. And although none of us are experts on health advice, just regular people posting as we go along, and possibly sharing information that we come across and think might be helpful to everyone else. It ALWAYS is important for us to do the research ourselves, for our own benefit. Also, it never hurt anyone to have a few glasses more of water (or beverage) a day, unless of course they are high in calories.