This list is deliberately short. Every item on it has survived multiple rounds of "do I actually use this" — most packing lists online are aspirational; this one is what's left after cutting the stuff that sounded useful but wasn't.
Clothing (11 items)
3 quick-dry t-shirts, 1 long-sleeve layer, 2 pairs of quick-dry shorts or convertible pants, 1 pair of jeans (yes, they're heavy — worth it for one non-technical-looking outfit), 5 days of underwear and socks (wash as you go, you don't need 14 pairs), 1 light rain jacket, and 1 warm layer that packs small.
Gear (9 items)
A universal power adapter, a small padlock for hostel lockers, a microfiber travel towel, a headlamp or small flashlight for overnight buses and dark hostel rooms, earplugs (genuinely one of the highest-value items on this list), a portable battery pack, a dry bag for electronics on boat transfers, a sewing kit, and a set of packing cubes.
Documents and small essentials (5 items)
Photocopies of your passport stored separately from the original, a padlock-compatible day bag, a basic first-aid kit, a reusable water bottle with a filter, and a slim, quick-drying travel wallet.
Takeaway: If you're unsure whether something belongs on this list, the test is simple — did you use it on your last trip without having to think about it? If not, leave it home.