Travelling light can make your travels all the more enjoyable in that it allows more freedom - you are free to be sidetracked into unexpected and unplanned adventures without being worried about stuff to carry. I've never carried more than 7 kg anywhere in the world.
The key to comfortable and independent travel is that your gear has gotta be light; if you can't carry your pack on one shoulder all day and even run for a bus, then it's TOO HEAVY! I see young girls bent double with the load, taking their dirty laundry on a tour of exotic parts of the world in their 'skyscraper backpacks'; and their 'day-packs', usually full as well and hanging to the front, are often bigger than my backpack - killing themselves!
If your gear is too heavy it will really hinder you and restrict your freedom unless you're travelling completely on tours where someone will be there to help you with it. Don't fret and be anxious about 'what to pack', in most countries you can buy almost anything you need along the way
Less STUFF will allow you to carry your pack on your shoulder at all times; you won't have to put it down on the gobs of SPIT (tuberculoses!) that are all over bus and ferry depots. You can sit with it on your lap in a tiny Asian bus or taxi, and it will go as carry-on luggage on aircraft. While fellow backpackers are still waiting at the baggage carousel, you can be out and away on your journey. If you must have a 'day-pack' then you can find a little lightweight nylon one that will scrunch up to the size of your hand.
You may need help if you have a shoe fetish. As recounted in Chapter 23, I once shared the carrying of a bag of shoes-- a 'shoes only' bag--with an English woman in Mexico; she had left home with her entire collection because she couldn't make up her mind which ones to pack!
I met a couple carrying an electric clothes iron; the ironing-board would have been preferable if I were forced to make a choice between the two - for surfing!!
I saw two medical students whose first-aid pack was bigger than my backpack and they were constantly popping pills - just in case!
Then there were two guys sharing the handles of an IT bag - plugs and adaptors for everything, everywhere and anywhere in the world. And they had it all; they were so busy with these gadgets that there was little time to look around at the real thing. But then, that's how many travellers are nowadays, blind to the new and exotic environment and falling into holes in the ground while checking their phones!

Here's a list you might find helpful:
* EAR PLUGS - may well be the most important item of all - a good insurance for your sanity.
* Only 1 extra shirt, and pants/shorts that can double as swimmers. 
* Only I pair of extra socks. If they don't dry overnight, just hang them on your pack next day. You can wear them on your hands while sleeping if there are mosquitoes about - extra clothes means you are carrying dirty laundry. A good rule is one wearing, one clean or drying.
* A wine cask bladder as a pillow - good if it's wrapped in a shirt or something and much softer than most backpacker hotel pillows - or those in any hotel in Japan! Be sure to arrange it so you don't wake up with the tap stuck in your ear!
* Frisbee - to make friends with the kids and keep you fit.
* Notebook (small) and pen to write new words as you hear them, a good way to learn the lingo. Keep it in your pocket so that you can whip it out to practice on the natives.
* Guidebook - better to download the chapters than carry a heavy book, then photocopy others if necessary - if you can find a traveller to lend, (that's illegal). A book can weigh a kilogram or more. An eReader is a good idea. Purchase and download chapters from Lonely Planet before you set out, but you can do that anywhere in the world that has internet access.
* 'Escape' Book - tear off the pages as you read to save on weight. Or carry that eReader.
* A bar of common (laundry) soap to wash both body & clothes.
* Measure out your shampoo if you have to carry it, count your disposable razors and shorten the handles, or grow a beard - if you're female make up your own mind on this one!
* Small flashlight for reading etc. LED is best, candles are dangerous in bamboo huts, or carry an 80-watt bulb - but that may blow the fuse, cut the generator or burn down the hut!
* Roll-on insect repellent. You can find little sachets of repellent in most tropical countries.
* A small chamois or micro-fibre towel instead of a big bath/beach towel. 
* Plastic clogs or flip-flops as well as the walking shoes you are wearing when on the move.
* A few safety pins and some string to hang up your gear and keep it off the floor and insect-free. Safety pins are lighter and smaller than clothes pegs.
* A USB memory stick with your contact addresses and copies of your documents. This can go with your passport & bankcards in your THIN money-belt INSIDE the waistband of your trousers, better than the conspicuous bum-bag.
* Snorkel & mask, and fins cut down to fit in your pack, otherwise substitute with a sleeping bag or jacket/raincoat for cooler climes.
* Money: Keep only your immediate cash in your zipped pocket in small denominations, enough to get you through the day, rather than constantly having to dip inside your money-belt. Best to just keep the daily cash rolled up without having to attract unnecessary attention as you fumble thru a wallet while everyone stares at you advertising your wealth. Keep a few larger bills in a separate pocket but still easily accessible. Cargo pants/shorts with zip pockets are a good idea.
* You can put your money-belt and passport in a plastic bag and bury it all in the ground if you're going to be in a remote area for a few days, swimming etc.
* Big, conspicuous cameras can be a problem - best to carry a small, compact type in a belt-pouch. Carry only unimportant items in your pack.
* A second or third bank/credit/debit card - ideally one to access a second account - some ATMs just eat them up.
* Small items to give as gifts - cheap eyeglasses are appreciated by older people in remote places, pencils and other little items for kids.
I also carry harmonicas and guitar picks. Guitar strings to give away - a rare thing in most places.
*And finally: Develop a stutter and practice it; much more effective than tears when you come up against immovable bureaucracy.