When automatic worry thoughts appear, it can be helpful to challenge them. Most of the time the thoughts are distorting reality, working off flawed assumptions the brain is making, and overestimating threats. Bringing some logic into the equation can be helpful.
However, when our goal is to become 100% certain about a worry thought (e.g., “I need to know for certain whether the odd look that person gave me is sign they are judging me”) we get stuck in a never ending argument with the worry thoughts. The worry thoughts often respond, “Yea, but…” to our logical challenges.
When it becomes never ending and circular, it’s a sign we’re pursuing the impossible: 100% Certainty. This pursuit is hard to give up because if we achieve it we’ll be free of worry thoughts and uncomfortable body sensations. It’s just not possible to achieve though.
If you find challenging your worry thoughts is helpful and brings some resolution to the doubt, then keep doing what works. If you find that it’s circular, it’s usually best to acknowledge that you’re seeking 100% certainty, acknowledge that it can never be achieved, and instead focus on building up a tolerance for uncertainty.