What One Carry-On Actually Holds After Six Years
Every packing list online is aspirational. This is an inventory, taken after the fact, of a bag that has been on every trip on this site.
The rule that did the work
I did not get to one bag by buying a better bag. I got there by unpacking properly after every trip and putting the unused items in a box instead of back in the wardrobe. After about a year the box was fuller than the bag, and the decision made itself.
The rule I settled on is that anything I did not use on two consecutive trips comes out permanently, with one exception for genuine safety items. It is unsentimental and it works, because it replaces guessing about what I might need with evidence about what I actually used.
What survived
Clothing is four days of it, in one colour family so everything works together, in fabrics that dry overnight. This is the entire trick to travelling light and it is not a secret: you are not packing for the length of the trip, you are packing for the interval between washes.
One warm mid-layer and one waterproof shell, regardless of destination and season. The shell has been used in tropical downpours and on alpine ridges in the same year, and it weighs almost nothing. This is the pair I would never cut.
A very small first aid and medication kit, a universal plug adapter, a battery pack, and a cable set that covers everything I carry. Then one notebook, which is heavier than a phone and stays in anyway, because I write more and better on paper than on a screen and this whole site is built out of what ends up in it.
The three things I keep repacking and never use
A travel towel, because I have never once stayed somewhere that did not provide one. A padlock, for hostel lockers I have not used in four years. And a spare pair of shoes, which has been carried across three continents and worn approximately twice.
I am aware of all three. They are still in the bag. The honest reason is that removing them feels like tempting fate rather than saving weight, which is exactly the reasoning the box method was designed to defeat.
If you want the real advice from six years of this, it is that the last two kilograms are psychological rather than practical, and that getting from a heavy bag to a light one is easy while getting from a light bag to a lighter one is mostly about admitting things to yourself.