First of all, welcome to the forum, Hal!
Second, that’s an interesting question. As a kid, April Fool’s pranks/jokes were generally harmless, and more along the lines of “school was cancelled today,” and then yelling “April Fool” once the other person had started to believe the line. Alternatively, kids might try to scare each other. Seems as if people haven’t grown out of that mentality, taking the easy, “kid’s stuff” route rather than trying to come up with a more complicated hoax.
ETA: Whoops, I didn’t realize that you’ve actually been here longer than I have! I guess I should say welcome back from lurkdom, instead.