Does anyone have suggestions for the essential things to take travelling with you?

this is my shopping list:
-> 1st aid kit
-> Travel Towel
-> Sleeping bag liner (linnen)
-> Water Purifying tablets
-> Mosquitto Repellent/net
-> Jesus Sandels

And then this is the stuff i have:
-> Backpack - yay!!
-> Swiss Army Knife
-> Travel Iron (if i can nick it off my mam)
-> Sleeping Bag

I'm sure there are other things i need!! I always managed to make a list and then lose that list... and try to make another one and then lose that.. consequently the list gets shorter and shorter everytime i read it!

but if anyone has anything to add to my excellent :) lists then post a reply thingy cuz that would be a GREAT help!!

bis spater
luv-k,x