There have been lots of movies about people who suddenly become smarter, or who use the part of their brain that normally goes “unused”: John Travolta’s character in “Phenomenon,” Scarlett Johansson as “Lucy,” and Bradley Cooper in “Limitless.”

These movies operate from the premise that humans use only 10% of our brains, and what would happen if we used all of it? This is actually a myth. But the idea that we could take a pill that would give us a photographic memory, and the ability to learn and analyze at a superhuman rate is intriguing, and inspiring.

I love these movies, and the idea that we are all capable of so much more – that we all have untapped potential.

We may not be wasting our brain power, but many of us do waste time. Maybe I could learn how to play the cello or speak Chinese, if I spent less time watching movies and TV. But that’s not going to happen. So let’s talk about the show:

“Limitless,” the TV spinoff of the film, passes the higher intellect torch to Brian Finch (Jake McDorman), who gets a job working for the FBI after taking the brain-enhancing drug NZT.

It’s a great hook, but I’m not sure it will be enough to hold onto viewers. It’s slipping rather quickly into the formulaic crime show category, which is what happened to the “Minority Report” spinoff. We want sci fi, not another “CSI.” Talk about untapped potential.

“I swim in it, I drink out of it. There’s really no wrong way to use a margarita pool.”

The Last Man on Earth

“The Last Man on Earth” poses a different what-if scenario: What would you do if the world’s population succumbed to a massive epidemic and you were the last person left?

If you were Phil Miller (played by Will Forte) you would steal art and artifacts from museums and use them to decorate your new mansion. You would have an inflatable pool filled with tequila and margarita mix.

And you would become so lonely for company you would make friends with volleyballs à la “Cast Away” and get so desperate for love that you end up hitting on a mannequin.

This very funny post-apocalyptic comedy hits just the right notes of loneliness and hilarity to keep me coming back for more, even if the title no longer rings true (it turns out he’s not really the last man).

Now in its second season, I was a bit skeptical of its ability to maintain its momentum. It seems like the premise could run out of steam at any moment, but “Last Man” always has another trick up its sleeve.

In one moment it’s a comedy with heart, and in the next it’s completely heartless. It’s stupid and brilliant at the same time. It turns out it’s not about the end of the world at all, but about the human condition and our vulnerability.

(Photos: Limitless, CBS; and The Last Man on Earth, FOX)