You never braak even when wind is involved. Since wind resistance is proportional to the square of the (wind) speed the handicap of a headwind where your speed added is always much larger then the benefit gained when your speed is subtracted.

Skipping the details, imagine you ride 15mph up and down in a 5mph wind. In still air at 15mph the drag factor would be 225x. Going upwind it jumps to 400x (a big penalty for only 5mph wind speed). When you reverse and go downwind the effective speed drops to 10mph for a drag factor of 100x.

So upwind you're penalized by 175 force units, but downwind you only get back 125.

That's in a perfect world, but as anybody who spends much time riding in wind can tell you, the world is anything but perfect. So after you fight a headwind all morning, and get psyched for that easy ride home, the wind also reverses an it's another tough stretch up wind. Nobody likes hills but at least they play fair and stay put.