Because the Truth Does Not Care What we Think.
The truth is the truth, period. Like the laws of nature, there is nothing you can do about the truth. It is what it is. It makes no difference to the truth, whether you believe it or not. Believing lies instead of truth will ultimately result in regret and futility. But choosing to boldly accept the truth will give you a solid foundation upon which to structure your entire life. This eliminates regret, because the truth is eternal. Truth never results in futility.