One day... We forgot a simple command in Linux. we solved it by searching on Google, but this command was often forget and frustrating. And I realized that there are many scenes of this “often forgotten”. For example, “Answer to a secret question on some site”, “Company postal code”, “Name of the person in the next seat”. And this Forgetman was born when it was assumed that the world is full of things that people don't need to remember. That's right ! leave everything that is hard to remember to "forgetman" !