Cole shrugs! He doesn't know that much, just that he doesn't need to drink, so most of the time he doesn't. It's honestly as simple as that.

"I don't know. I just don't do it because why would I?"

It looks messy and it can spill everywhere. Besides, what else would he drink for, pleasure? He can think of plenty of things that would make him feel better than drinking juice or something like that.