It's more existentially terrifying if the wish operates differently. Instead of adjusting reality to make your words true, it simply constrains you to only be able to speak true and correct statements. So when you try and speak, "no, I have three wishes left," what comes out is "I have two wishes left."

In particularly powerful forms, this wish could be used to solve metaphysical and existential questions. You literally can only speak the Truth. Want to know the day you die? Pick a random date and try to say, "I will die on ____ from ____." Your actual date and cause of death will come out instead.