I don't drink enough water. I know it. I have often read that by the time one is actually thirsty, that the body is already dehydrated. And I've found that to be true for me. By the time I'm thirsty and remember to drink water, I end up guzzling it down. But, I'm running around too much at work to carry a bottle around with me. Often, there is a collection of lost or forgotten water bottles by coworkers each day, as they forget where they put theirs. I' have a water bottle in my bag, but I'm not usually where my bag is stashed. I'm just not the kind of person that has a water bottle tethered to me.
I pay for it though. My urine is sometimes darker than it should be. I notice my skin is really dehydrated. And sometimes I have leg cramps later in the day. Sometimes, it's low potassium. But, more often, it's dehydration.
At home, I did size up to a 40 oz. water bottle. As once I settle down for the evening and sit for a movie, I often found my previous, smaller water bottle empty by then and had to get up to refill it.

Ideally, a 60 oz. water bottle would get me through the whole day. But, that would be too cumbersome to lift all the time.