It has to be physiological, that’s all there is to it. I’m sure the psychology plays in there as well – that’s inevitable – but it must be physiological. It is simply impossible that I could have done so many of the same things as him, and as so many of my other friends who ended up as ensnared as him, and escape scot-free, with nothing worse than a few emotional bruises and some fascinating near-death-experience stories to show for it? What is it in his chemistry that dictated that he would try these things and become dependent on them, unreasonably and insanely drawn back them even though well aware of the inevitable consequences they would have on his life, while I would be able to brush it off and walk away? Why is it that, at a party, I feel no pang of regret drinking a Sprite instead of a beer, out of solidarity with him, yet he yearns for the beer? How absolutely terrifying, to think that our body could demand something, anything, so strongly as to overrule our conscious will!