House: Are you using your inhaler? Patient: All the time. House: You sure you're using it right? Patient: Do I look like an idiot? House: No.Why don't you show me how your inhaler works? Hahah, House MD tv show quotes
It makes perfect sense that he would do this because he himself is such a huge fan. This is SO MUCH FUN for him. Capaldi is such a glorious geek about it. It's lovely. Having a fan of the show as the Doctor works. He knows the show inside and out, takes it seriously and will do whatever he can for it. He is so caring and passionate of the fans and his role. Capaldi becomes The Doctor outside the episodes as well. It’s just brilliant and rather epic.