I can speak from expirience on the power of tobacco. I have not been to a shelter ever, but I have seen entire plans change and decisions be made that changed a particular course of action just by giving someone a cigarette or two. Just remember, that cig's do have a shelf life and you will need to replace them!
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On occasion of every accident that befalls you, remember to turn to yourself and inquire what power you have for turning it to use. - Epictetus