Why everything is getting true expect false in ruby if condition (e.g: puts "Hello World" if 1)

In Ruby,

Why all the true, numberic,floats and strings are getting true while checking with if condition, Except false?

Examples:

   1.9.3-p551 :031 > puts "Hello World" if 0
   Hello World
   => nil

   1.9.3-p551 :032 > puts "Hello World" if 1
   Hello World
   => nil

   1.9.3-p551 :033 > puts "Hello World" if 2
   Hello World
   => nil

   1.9.3-p551 :034 > puts "Hello World" if 200
   Hello World
   => nil

   1.9.3-p551 :035 > puts "Hello World" if "Ruby"
   (irb):35: warning: string literal in condition
   Hello World
   => nil

   1.9.3-p551 :036 > puts "Hello World" if "Rails"
   (irb):36: warning: string literal in condition
   Hello World
   => nil
   1.9.3-p551 :037 > puts "Hello World" if true
   Hello World
   => nil

Except

   1.9.3-p551 :038 > puts "Hello World" if false
   => nil
   1.9.3-p551 :039 >