Everyone is different so everyone may not need the same stuff. What works for me may not work for you or someone else.
Ok having said that, there are now still many variable's that one may need considering. For me the first thing you need is the correct state of mind, you must KNOW that you can. Preparation is also very important, and by this I do not mean send bike in for a service and check before you leave (this is also a good idea, if you do not maintain your bike yourself). By riding you learn more about your bike every km, because every ride is different. Know your bike, learn the weakness and learn how to solve them (either permanently by "modifying" or how to "fix" it on the road.
Once you are confidant in this you shall have a fair idea of what you need for the bike, oh and I never travel without my full puncture repair kit (this includes 2 spare tubes).
As far as clothing, food, and camping equipment goes again we all differ, I always bring a small gas stove, my espresso pot, coffee, a pot (varkpan) some emergency food in the form of pasta and sauce, my braai grid and a tin or 2 of fish or whatever and some dry biscuits.
Now if I were to be riding for days in isolation, ( I find this difficult as with my bike needs fuel) I would pack different.
Then I also prefer to shower (or at least wash) every night and sleep well, so I do pack a tent, sleeping bag, mattress, pillow, and 3 changes of clothes. Some are very happy to go without these.
Ok in a nutshell you need to find out what works for you.