You're very serious about something.

This is from the anime series "Prince of Tennis". Tezuka, the captain of Seigaku tennis club is well-known for being a very serious, pokerfaced character. He has a special tennis trick called Tezuka Zone which he only plays in serious matches, where regardless of where the opponent aims to hit the tennis ball, it always gets sucked in towards Tezuka. Thus a serious character plus a serious situation only results in double the seriousness!