It's a pretty dramatic moment in The Lion King. Simba, Pumba, and Timon are laying in the grass looking at the stars and Simba is left wondering about his purpose in life. He walks off emotionally and flops down on the grass, the dust swirling in the wind. And, look! That dust swirling in the wind looks a lot like it's trying to tell him something. What could it be? What is the most important thing in life? Oh, it spells "Sex."
The widely used reasoning for this is that it's actually spelling "SFX," short for "special effects." But that's not nearly as fun, so we won't listen to that reasoning.