For Realsies

April Fool's Day is celebrated in the US, France, Scotland, Iran (!) Spain, Portugal, India and Denmark.  All of the celebrations are similar in nature - playing jokes and practicing tomfoolery on unsuspecting others. 

No one knows for absolutely positive, but it is widely believed to have begun being celebrated in the late 1500s when the Gregorian calendar was adopted (evidently internationally) and the New Year's start was moved back to January 1st, away from the old date of April 1st.

This is a very old trick - you only need a spool of thread and a needle.  Thread the needle, pull up your shirt or sweater and push the needle through the fabric.  Nestle the spool somewhere convenient (inside your bra is a good spot but that kind of rules guys out) and take the needle off of the thread.

Kind-hearted people will come along and say, "Oh, you've got a thread" and helpfully lift it off - except it just keeps coming and coming...