Why do people now need constant access to water bottles?

I'm not questioning the need for hydration. I make it a point to drink at least 8 cups of liquids a day, and also eat plenty of foods that are high in water content.

But I don't know why we constantly need a bottle of water next to us now. When I was a kid, we drank from water fountains at school, and had milk or water at lunch. We never had water bottles in our classrooms. If I'm exercising, I just have water afterwards...I have no desire to drink in the middle of the workout. If I were running a marathon or something, of course it would be different. But I don't see why I need to drink in the middle of a 30 minute workout. Am I just strange?

ETA: I appreciate everyone's input. It seems like a lot of people are in situations where they don't have easy access to water, and that many people prefer to constantly sip water versus just drink a cup quickly when they have a chance. I have easy access to water almost everywhere I go, but I can appreciate that others don't. Whatever works for people is what they should do.

ETA2: Many seem to be offended by this post. I really don't care what others do. If you feel better drinking lots of water, go for it. It doesn't bother me, and I don't know why so many people seemed to think it did. Many commenters also said they were on medication or had medical conditions that made them need more water, and that's totally reasonable. Many said they didn't have easy access to water, and I think it's very reasonable to carry a water bottle in that situation too.

I do have to wonder about the statement many made regarding how you need to drink water before you're thirsty, because when you're thirsty, you're already dehydrated. I have heard this many times, and I guess I even abide by it, because I set a water goal every day and seek to drink that much, regardless of whether I'm thirsty. But really, I'm not sure it makes sense. How could we have survived as a species for as long as we have by being chronically dehydrated? Wouldn't people naturally just drink when thirsty? I can't imagine cavepeople would drink water when they weren't thirsty. A cat or a monkey only drinks when they are thirsty, don't they? Are those animals chronically dehydrated?

Is the claim that our modern, unnatural environment makes us dehydrated, so we need to drink past thirst to overcome that?