Random beer thought of the day..

And one that will probably need more thought. It is interesting that so much of ones impression of a beer has to do with outside factors. The temperature, what kind of day you had, even what you ate for dinner all have an effect on the beer you are drinking. Of course it is up to you to be able to separate those 'outside influences' in a beer evaluation, but there are times that its very hard and nearly impossible to do so. The question then is, should you worry about those or just add them to the evaluation?