Basic physics 100% tells you you won't gain weight in that case.

Are you certain that humans can properly digest gasoline and make use of its calories?

I'm sure that they can't. That's why they won't gain any weight with such diet.

So you're saying that the type of calories you consume makes a difference, not just the amount???

I'm just saying that whatever calories you consume you won't have more net gain of weight than contained calories you consume minus calories you burn.

Regardless of whether calories are completely indigestible or totally digestible the above still holds.

I think the assumption with trying to be healthy and track your calories is you are eating a healthy and balanced diet, and not things like potato chips, candy, or gasoline all day. Then with healthier food choices a consistent value for you in your life, you don't have to worry about that Starbucks drink that's 600 calories because you just wouldn't be drinking those things with this new mindset. Then it doesn't even matter your metabolic rate either; if your diet is consistently healthy and you are measuring calories and your weight on the scale, then you can dial back caloric intake and see results on that scale.

All I know is that if I gorge myself on only eggs and fatty ribeye steaks for weeks on end, then I’ll lose fat, gain muscle, and look good naked. Burn if I eat carbs and drink beer then I gain belly fat and look terrible naked. I never count calories.

Drinks, not just booze, are sleepers for caloric intake. A can of coke or a small bottle of gatorade are 130 calories. Then you have some people who literally hate the taste of water for some reason, so every drink they take of a liquid comes with calories. Just switching to water alone for a person like that could cut out hundreds of calories right there with no other changes to diet or lifestyle.