When someone learns I don’t drink coffee I get the same puppy-turning-his-head-in-a-puzzled-way look. I sometimes say, “my mother is a coffeeholic and I got my lifetime fill as a fetus.” Usually their confusion grows.

It was harder when I owned a coffee shop for six years. You’ll understand when you buy your first bar.

I rarely drink alcohol either. And yes, people always offer and then feel compelled to press for an explanation when I decline. What is that? Some responses I’ve used:
“I’m okay. I drank last year.”
“No, my bladder/liver/kidney is already mad at me.”
“But I want to remember your stories this time!”
“Your call: If I lose my filter you’ll learn the truth about that shirt/makeup/haircut.”
“No, I think one of us should keep it in our pants.”
“If I drink and you drive neither of us will get outta first gear.” <— no one knows what that means, including me, but they invariably laugh and back off.
Is that a win?