That "jumping around" thing jessica_dixon mentioned is the worst. It's like trying to draw while wearing oven mitts. Getting a clean sketch on a touchpad really is next level skill.

Remember those old guidebooks sometimes had wrong distances though. I found a card from a trip near Bishop where my written mileage was off by two whole miles because a trail got rerouted. The smudged notes were part of the charm, but man, getting lost added unplanned adventure.