I am not good at this holiday. Why can't we just have April, without the Fools?
Wikipedia says that April Fools has been happening for a long time, and that foolishness has been associated with the first day of April since the 1300's in England.
A not very reliable looking site called "April-Fools" says that it is because in the 1500s the calender was changed from an April 1st start date of the year to a January 1st start date. Interesting. I like this theory.
Snopes, which I think is more reliable, says that while the calender change is a possible origin, there are other theories including finicky weather around the beginning of April, young animals being naive and easily caught, or a vestige of a Celtic celebration.
Then of course there is France, who don't celebrate April Fools they celebrate poisson d'avril, or April Fish. In French class in high school we used to celebrate by cutting out fish and sticking them to each others backs when the person wasn't looking.
Either way, this is a weird holiday, wouldn't you agree? Lets just get on to spring!