He frowns at the thought of 'wasting weed', as Shin puts it. That wasn't his intent. But maybe he did if he wasn't doing it right. "Maybe I'm not? I mean, how do you do it? Like a cigarette? Just the in and out?" He's probably going to sound stupid here, but maybe.. if he is doing it wrong, by fixing that he can unlock an essential experience to enjoying life. Or another vice. Both very similar.