We've always assumed that cognitive decline was just the cost of a long life. But some people manage to sail into old age without ever paying a price in mental sharpness.

The ol' memory banks tend to slip a little as we get older. No surprise there.

It may be the ultimate symbol of human mastery over nature's power: fire. On this edition of Clever Apes, we consider why flames fascinate us. Eons of evolution have written fire into our DNA -- no wonder kids like to mess with matches. AUDIODownload this episode, or subscribe to the podcast.

Science doesn't always tell us what we want to hear, and our record of accepting unwelcome findings is less than stellar. We have been known to shoot the messenger; or at least lock him up until he concedes that the universe revolves around the earth.

So much of science is about finding patterns -- repetitions that let us predict outcomes for given circumstances. The universe is full of these rhythms -- from the vibrating loops of string theory to the orbits of stars and planets to the pulsing of our heart.

What if during the World Cup finals, a unicorn pranced out onto the field. Or a woman on stilts appeared. Or, say, Wilford Brimley. You'd probably notice, right? Not necessarily, as psychologist Daniel Simons has shown.

The apes are us -- the latest version of a critter that has evolved to be curious. This thirst of ours seems to be hard-wired -- to know ourselves, to find truth and to seek beauty in the universe.