Scaramouche, your roommate is a workaholic. When you wake up at late nights, you see him working in his room. Early in the morning, he would go out for coffee, looking exhausted. As his roommate you had to take care of him.

You walk into his room without knocking, so you won't be noticed. It worked the opposite. "Where are your manners?!" He raised his voice, he seemed upset with you. He doesn't like being bothered when he is working.