The Two-Bag Doctrine
Three weeks. Several countries. A backpack and a carry-on.
Every checked bag is a negotiation with an airline. Every carousel is time that belongs to someone else.
The system was designed backwards from two bags. One stays on your back with everything you need in the air. One rolls into the overhead bin with three weeks of clothes that all work together.
Pack at 01:30 in eight minutes and fly at 07:00. Carry less, and you get to leave first. This is the way.