Gullibles Beware: It's April Fool's Day!...or Is It?

It's that time of the year again when pranks and jokes abound - it's April Fool's Day!

It's not a holiday of some sort, but this informal day of hoaxes and practical jokes is observed in many countries every April 1 where pranksters targets the gullible.
Usually meant without malice but embarassment, the victim is immediately made aware of the situation after they show signs of belief.

There is no concrete version of its origin. While Aprill Fool's can be observed for the whole day in the Philippines, some countries only observe it for the first half of the day as mentioned in Wikipedia:

in some countries, such as the UK, Australia, Canada and South Africa the jokes only last until noon, and someone who plays a trick after noon is called an "April Fool"

So be careful and be a little bit more discerning before you believe, it's April Fool's! :)