Facts You Didn’t Know About Valentine’s Day From its bloody origins to its sweet, chocolaty modern day traditions, these are 25 interesting facts you didn’t know about Valentine’s Day. 25 The most popular theory about Valentine's Day origin is that Emperor Claudius II didn't want Roman men to marry during wartime. Bishop Valentine went against his wishes and performed secret weddings. For this, Valentine was jailed and executed. While in jail he wrote a note to the jailor's daugter signing it "from your Valentine". 24 In Victorian times it was considered bad luck to sign a Valentine’s Day card. 23 Based on retail statistics, about 3 per cent of pet owners will give Valentine’s Day gifts to their pets. 22 About 1 billion Valentine’s Day cards are exchanged each year. This makes it the second largest seasonal card sendi...