Again, do you hold a belief that there are no unicorns? No teapot orbiting Venus? No people with superhero powers? You see how this list could be practically infinite.
Are you going to hold all those negative beliefs in your head all the time? Worry about them? Live your life based on them?
Worrying about countless things that have no evidence of existing is a lot of work and pretty impractical. Hence why most non-delusional people with at least some critical thinking skills restrict themselves to only considering things for which there is some evidence.
You're so close to getting it!