Today I Learned

validates_presence_of won't work with booleans

If you want to validate that a value for a particular boolean field exists (using ActiveRecord instead of null constraints from you DB), then you cannot use validates_presence_of. This is due to the way that the blank? works on an object with the value false. Instead, you will need to use this for your validation:

 validates_inclusion_of :field_name, :in => [true, false]