Filters in a given context separate out the winners from the ones that aren't viable.

Getting caught in the filter knocks you out of the game.

Successfully passing through the filter doesn't feel like anything. You just didn't die, just like the previous time steps.

You can only notice passing through a filter only by looking around you and seeing how many fellow travelers were knocked out of the game.

It's easy to not notice these because when someone's caught in the filter it's often not an attention-grabbing explosion but a quiet bowing out.

Imagine that all of the entrants are working hard but only some survive. Making it through the filter is in that case somewhat due to luck.

You can see your own hard work, but you can't see the luck required to pass through the filter.

So the winners who make it through the filter often erroneously attribute it primarily to hard work, even if luck was a large component.