If a recipe calls for 12 oz, I’ll usually cook the entire 16 oz of pasta, scoop out a quarter of it before using the rest for the recipe, and save the extra 4 oz in a Tupperware for the next time someone just wants a single serving of pasta that they’ll throw something on. Lunch for work, picky 11-year-old who doesn’t want to eat what everyone else is eating, quick dinner for a busy night when everyone is just foraging for their own thing….you get the idea.