I did this in school, and there wasn't any rule about "You have to have candy and cards for everyone." It was encouraged though, because we were in 1st grade and we knew it was nice to be nice.
But I had eyes in particular for this one girl. Her name was Déjà. I pondered constantly on how to perfectly craft the Valentine I would give her. I wrote her a letter too, or at least started to write it. My family heard I had a crush on this Déjà girl, heard from me because I told them, and they heckled me for it. Not in a mean spirited way, I know they meant well. But from that day forward, I saw romance as a "mushy" thing. I didn't wanna be mushy, that was embarrassing. I wanted to be cool.