A backpacking packing list is not a car-camping list with the chairs deleted. You carry every ounce, so the Big Three (pack, shelter, sleep system) set the budget before snacks or a camp pillow even get a vote.
Use worn vs packed as a second filter: clothes on your body do not live in the pack, but they still count. The checklist below is a three-season overnight baseline. Cut aggressively for an ultralight overnight; add insulation and a more serious sleep system when nights drop.