Occasionally, I have to rub my fingers over surfaces in what I consider balanced patterns.

So if I run my finger over the cover of a book for example, and it starts like this.

Up, Down.

Then I have to proceed with;

Down, Up
Down, Up
Up, Down

I don't know why, and it's not all the time.

EDIT: So yes, sometimes it looks like I'm trying to input the smurfing Contra code on a book or magazine. Damn analog video games.