How does a blind person know when they're done wiping?

I’m amazed that so many people appear to inspect the toilet paper after every wipe, to see if it needs doing again. Apparently I’ve developed the superpower of being able to tell when I’m done wiping by feel. I thought most people were the same way.

If I was told I was losing my sight, “How will I know when I’m done wiping?” doesn’t even begin to register as a concern.