I had my first 'free' meal today, and compared to what I've been eating for the past month, it was pretty high in sodium.

Now I literally cannot stop drinking. I am soooo thirsty!

Is this normal? Is this how sodium causes water retention?

Just curious...

It's normal, and it's your body's way of trying to flush out the extra sodium. Drinking lots will make you retain less water than just drinking a bit.