Going camping to a music festival

I asked a camper (aged 20, male) who has been to a music festival before and camped overnight what sort of items they took. Below I have listed everything that they bought/already had to take with them:

75 ltr Bergan rucksack

Sleeping bag

Tent

Water bottle

Sleeping mat

Knife

Fork 

Spoon

Torch

Speakers 

Phone
I also asked them what they would take next time that they felt they had needed, they said:

A small cooker

Fuel to cook stuff on

A lighter

Camping stool