It is your life and you can believe what you want. Some people are so sure that the way they see things is the way it is that they are willing to kill for their beliefs. Religious and political dogmas are examples of a thinking style that extends to some sports fans, nutritional supplement vendors, and other true believers. We see things as they look from a particular perspective. No perspective is valid and complete; each introduces a bias.
“A casual stroll through a lunatic asylum shows that certainty means nothing.”
– Nietzsche
I recently had to choose a photo of myself for this website. Naturally, I selected the most flattering one. Then I had the thought: “You can’t use that one, it makes you look more handsome than you really are,” then I thought: “Actually, it’s the other pictures that make you less handsome than you really are.” Needless to say, this internal dialogue reflects my self-focused doubts rather than facts about the objective world. I did not alter any of the photos, so no one is more valid than another. Each shows how I look from a particular angle, with certain lighting, at a particular moment in time. There is no “most valid” photo of me, so I cannot use validity as the basis of selection. Instead, I’d be wise to choose the photo most likely to do the job I want it to do: To evoke a favorable reaction from the viewer.
Your reaction to the things that happen depends upon the perspective from which you view them. Since there is no correct perspective, Nietzsche recommends you choose the way you view things on the basis of utility (not validity).