Taking as much as possible with you to be sure that nothing is missing and to foresee all weather conditions and all situations is good…but not very practical and untenable over a long distance. “To travel light is to travel happy”: I subscribe to this completely.
Where necessary, it’s always possible to find a town or area where you can get hold of or rent what you don’t use permanently (specific equipment for trekking or mountaineering, for example). You can renew your “wardrobe” on the way.
Consequently, for the more rudimentary things (toiletries and clothing), my essentials are:
You quickly get used to a lack of cleanliness – or you adapt your appearance…but you often find yourself wearing the same T-shirt and Bermuda shorts for days/weeks…
*solid backpack – side opening (like a suitcase and not at the top)
*a light sleeping bag, not too cumbersome
*a sleeping bag sheet/sarong (multi usage: towel, protects against dirt/or catching anything, cloth, defines your “territory” etc…).
*a mosquito net
*a T-shirt with long sleeves
*belt with an inside zip (invisible and allows you to place some dollars there in case of emergency) and ventral pocket
*multi use penknife
A few clothes are enough.