Let’s take a hike on the coast from San Francisco to Los Angeles to visit our friends in Newport Beach. I’ll whip out my map and draw our route down the coast

The line is about 400 miles long, we can walk 4 miles per hour for 10 hours per day, so we’ll be there in 10 days. We call our friends and book dinner for next Sunday night, when we roll in triumphantly at 6pm. They can’t wait!

We get up early the next day giddy with the excitement of fresh adventure. We strap on our backpacks, whip out our map, and plan day one. We take a look at the map. Uh oh …