Judi's Southbound Logic

Wendi and her buddy were heading to the Hard Rock Cafe in Dallas accompanied by Judi. They'd left their car and were heading out on foot. Somehow the discussion got to how Judi had figured out the correct direction to head. Wendi's buddy taunted, "I bet you don't even know what direction we're going, do you?" "Sure I do," Judi said, "we're going South." Sure enough, that was true. Wendi figured that Judi took a look in the sky, noted the position of the sun, and figured it out. So she said to Judi, "That's right -- how'd you know that?" "Easy. We're going downhill, so that MUST be south!"