Like, I can be eating the most delicious food, and not be nearly full, but then I suddenly remember that I'll drink water afterwards, and that enjoyment is gone.
I'll just be thinking about that water. Usually I try to force myself to finish, and just treat the water as a treat at the end.

And I know people tend to drink water while eating.
No fucking way. I get a sip, and then I can't stop. Either the cup empties, or I fill. In the former case, I'll still think of water, the cup must be refilled.

But hell, I even flush soda and juices down with water.

Probably the only food that doesn't have this effect is raw fruits and vegetables. That cucumber doesn't really ask for water.