lol, this what you state is very true. I also didn't have the right pan, wood and a mate who was constantly building up the fire in a way wich was totally contradicary to the way I'd like to. finally it had to be a low profile fire. not the ideal sercumstances 

The thing with cooking over a fire is that there are infinite variables that you can use to control the heat, and learning them is more of a science than anything else. Different woods burn at different temperatures, then you have to take into account the moisture in the wood if it is well seasoned or not, whether it was caught up in the tree or on the ground. The method used to lay the fire also affects the heat, the stage of the burn, ie. still have flames or just embers. The wind speed and temperature in the area you are cooking. The list goes on.
If you want to just boil food, then it's not a problem, but if you want to make more complicated meals outdoors then you really need to experiment a lot and not be too down when you burn dinner!