My flatmate and very close friend is a DJ and on Friday and Saturday nights he's usually out all night. He has a bad history of getting too wasted at these events, blacking out, and doing something stupid, waking up in mysterious places, and staying drunk/high for the whole weekend. He always promises he'll be home by morning, but it rarely works out that way. Last weekend was particularly bad. I care very much about him and when he does this to himself, it really upsets me. He's a very different person when he's drunk, and not the kind, nice guy I love living with.
I went to bed around 1:30 am. At 2:00 I woke up to the sound of him coming home. I said hi and went back to bed. He went to bed shortly afterwards (I never sleep when he's still awake). This morning he got up at 10:30 and went out. I figured he was going to buy more beer to stay drunk all weekend. I got up and sat on the sofa with my computer, and a few minutes later he came back - with a container of yogurt. He was sober and up long before noon. Then he started... cleaning!