How has Valentine's Day changed over the years?

To a degree. Card companies, chocolate factories and florists all know this is the time of year they can make big money. It's very commercialized. Also, it was reserved for lovers, but now people feel the need to buy something for mom or grandmother. Children have always exchanged Valentine's cards at school (don't know if they do it now) but we did it in elementary school. If you stick to the love of your life then it's simply less complicated.