I have now heard this theroy more than once. Lips become addicted to Chapstick! I mean once you start using it you lips want more. They need it all the time, like some dry mouthed drug fiend dragging himself through the city streets hungry for a hit.
It all starts innocently enough, with a day of dry lips that just need a little moisturizing...the first one is free. Then two days then three. Next thing you know you've got a full blown addiction. You're walking around town with dry irritated lips if you go a day without it, cracked and dying for another shot of the waxy goo. You look ridiculous with large red swollen lips, but you have to break the habit, you have to break the cycle!
You cave, and smear on some more...