Sometimes...I Just Don't Know

I'm a rather intelligent person. I scored a 30 on my ACT. I make pretty good grades. I know a lot of stuff. People compliment me on it all the time. But, a lot of times, more often than not, I find myself lost.
If someone came to you with a complaint, very simple, such as "I'm thirsty", what would you tell that person? Easy, right? "Drink something." However, what if that person were to say "I'm so thirsty right now. But, I think I'll wait til tomorrow to drink something."? It seems totally illogical, right?
This is where I am right now. I'm at a total loss for words. Why would the parched person refuse the one thing that they are in need of at the moment? It's not like they are withdrawing and need a hit of coke or something. It's water. It's nourishment. It's what everyone needs. Kinda like food. You gotta eat. But for that person to say nah I'll wait til tomorrow, just totally blows my mind.
I don't know. It's as simple as that. I don't know. And I'll probably never know. It's things like this that make me doubt my intellectual abilities altogether. I guess I'm not as smart as I thought I once was. Good thing there's Google I guess.
<3 J