Wondering why a direct comparison using "if" passes when the value is falsy.

nil_object.rb

class NullObject
  def true?;    false end
  def false?;   true end
  def nil?;     true end
  def blank?;   true end
  def present?; false end
  def empty?;   true end
  def to_s(*);  "" end
  def !;        true end

  def method_missing(*args, &block)
    self
  end

  def to_value
    nil
  end
end

if NullObject.new
  puts "I should not be here, isn't it falsy?"
end