The nice thing about logic is that it doesn't care about your biases, if you can show something to be internally inconsistent, then it's wrong.

I went through most of the Lockdowns not knowing what was actually happening, but knowing which narratives were demonstrable lies. You don't necessarily need real world data to show this, just use the data a person is using to justify their position to disprove them.

So I knew Covid wasn't particularily deadly, it didn't kill indiscriminately, the vax was never safe or effective, and lockdowns were never about health. I didn't need to prove the opposite (which we couldn't until after the fact) to know that what we were told was a lie.

Another easy one is: of someone tells you something is definitely true, but doesn't provide evidence, it probably isn't.

To this day, Youtube puts links on all videos discussion Covid that purport to show the "real" facts, but which merely lead to a government site with broad, unfalsifiable, statements, not studies or data. I assume, without further evidence, that anything they're trying to say is a lie.

Once you eliminate the possibilities, whatever remains, no matter how unlikely, must be the truth.