Dont worry about forgetting to take anything, there is NOTHING that you can get at home that you cannot get there. You will also find that it will be much much cheaper too !
The first time I went, I took a shopful of toiletries in case I couldnt get anything there. WHAT a waste of time ! After my girl had finished crying with laughter, she insisted that we go to the supermarket, so I could see what was available. I was amazed to find that it was just like being at home, and in a few respects, actually better !

I had most shots done, but in hindsight, I would not bother.
However, I would strongly recommend that you take some measure against mosquitoes and malaria.
The first time I went, I managed to avoid being bitten at all, even after going to some far out places, so I thought that I would not bother on my second visit.
Unfortunately, the little buggers nearly ate me alive one night. It only happened one night, which I thought strange, but I thank my lucky stars that I did not become ill.

Also, as others have said, drink only bottled water, and avoid ice if you can ( look what happened to Titanic ) or you will most likely get a nasty case of "runny bottom"