“Life is either a daring adventure or nothing,” the American writer Helen Keller once said.

At any given moment, some adventurer somewhere is boldly finding a way of pushing the limits. Take the Pangaea mission: a four-year global journey led by explorer Mike Horn, whose feats include crossing South America and Africa under his own muscular steam.

Are you breaking new ground? Here’s some motivation from some of the most pioneering people who have ever walked the planet – hard-chargers apparently wired to seek and succeed.

1. Bear Grylls

“I work on the principle that each day I am going to work for 24 hours until my eyes bleed – anything less is a bonus.”

- British adventurer, writer and television presenter 

2. Dean Karnazes

“I run because if I didn’t, I’d be sluggish and glum and spend too much time on the couch. I run to breathe the fresh air. I run to explore. I run to escape the ordinary. I run… to savor the trip along the way. Life becomes a little more vibrant, a little more intense. I like that.”

- Ultramarathon runner 

3. John Muir

“Thousands of tired, nerve-shaken, over-civilized people are beginning to find out that going to the mountain is going home; that wildness is necessity; that mountain parks and reservations are useful not only as fountains of timber and irrigating rivers, but as fountains of life.”

- Scottish-born American pioneer 

4. Fridtjof Nansen

“I demolish my bridges behind me – then there is no choice but forward.”

- Hardcore, multi-talented Norwegian explorer 

5. Jacques Costeau

“Every morning I wake up saying, I’m still alive; a miracle. And so I keep on pushing.”

- Undersea explorer and filmmaker 

6. David Livingstone

“I am prepared to go anywhere, provided it be forward.”

- Africa explorer