By most modern standards, Ernest Shackleton was a miserable failure.

He was not, despite his deepest wishes, the first man to make it to the South Pole; that would be the mustachioed mariner Roald Amundsen. He was not, in spite of his best efforts, the most famous explorer of his time; his former boss, the regally named Robert Falcon Scott, had that honor. He never even succeeded in translating his modest celebrity into a handsome income: when he died, at 47, on a small island in the southern Atlantic Ocean, he owed a small fortune that, in modern terms, would come to nearly a million-and-a-half pounds. Add to that his thick eyebrows, hangdog face, and penchant for spending most of his time by himself reciting poetry, and you begin to wonder if this is the same Shackleton who inspired generations of adventurers, not to mention a made-for-television film starring Kenneth Branagh.

And yet, despite his failures, Shackleton’s spirit was steadfast. “A live donkey,” he wrote to his wife, “is better than a dead lion.” And so it was with the donkey’s requisite stubbornness that he tried once more for Antarctica, aiming for the one record that hadn’t yet been broken: the crossing of the frozen continent. For nearly a year, Shackleton and his men fought with the treacherous ice and the creeping cold. Then the hull of their ship, exhausted by the extreme weather, cracked, forcing the crew to evacuate to the nearest secure landmass, the ominously named Elephant Island. The crew, Shackleton knew, would perish unless rapidly rescued. Along with five of his men, he boarded a small lifeboat and headed out for help, risking an ocean dense with icebergs and starved killer whales. He refused to pack supplies for more than four weeks, the amount of time he estimated the remainder of his men would survive without relief. So as not to burden the small vessel with unnecessary weight, nothing unnecessary, not even a Bible, was permitted on board. Instead, the captain instructed each of his men to tear their favorite passage out of the good book and place it in their shirt pockets, close to their hearts.

Were I fortunate enough to be there, among Shackleton’s men, I would have picked out this week’s parasha. One passage in particular, to be precise: the one about Moses dealing some street justice to an Egyptian officer. Here it is: “Now it came to pass in those days that Moses grew up and went out to his brothers and looked at their burdens, and he saw an Egyptian man striking a Hebrew man of his brothers. He turned this way and that way, and he saw that there was no man; so he struck the Egyptian and hid him in the sand.”

Growing up, I was puzzled by this story. Here, I thought, was Moses, future leader of the Israelites, purveyor of the Torah, and God’s BFF, acting all sly. Instead of standing up to the oppressor and making a statement, Moses looks around to make sure that no one’s watching and then makes his furtive move. It’s as if he subscribed to the Bart Simpson forensic school of thought: I didn’t do it, nobody saw me do it, you can’t prove anything. Would Rambo ever turn this way and that way before dispensing his holy wrath? Would Dirty Harry? Would Charles Bronson? Why couldn’t Moses, our hero of heroes, simply mutter a cool catchphrase, like “yippie-kay-yay, sun worshipper” or “hasta la vista, Pharaoh” and then kill the Egyptian with a neat karate chop? Why so timid, even when kicking ass?

It took me years to learn that Moses’s hesitation had nothing to do with the fear of getting caught. He was not, I’ve come to realize (aided by some of our finest commentators), looking left and right to make sure no one was watching. He was looking left and right for a far less prosaic reason: as many of us often do when we witness an injustice, he was hoping that someone else would step in and do the right thing. He was hoping that someone else, someone more confident and strong and fearless, would show up and give the Egyptian his comeuppance. Anyone, he was hoping, anyone but him.

Although he preceded the Talmud, Moses was nonetheless operating on that precious and wise Talmudic dictum: “In a place where there is no person, strive to be one.” There he was, and there was the Egyptian beating the helpless Hebrew slave, and there was no other person present to put an end to the violence. There was no other person, and so Moses strove to be one. And he did.

And here’s the beautiful thing, the key lesson that makes even grand figures like Moses and Ernest Shackleton perfect role models for the rest of us dull, unwashed masses: they both failed. Moses may have succeeded in saving his Hebrew brother from a thrashing, but the very next day he was ratted out by his fellow tribesmen and was forced to flee to faraway Midian. And Shackleton may have succeeded in saving his men, but he failed in fulfilling his expedition and died broke and heartbroken. But the lesson of both lives had nothing to do with missions accomplished. It had to do with striving to be a person where there is no other person to be found. It has to do with knowing how to be that person even, or especially, in dangerous, unrewarding, but ultimately unavoidable circumstances. It has to do with stepping up to the occasion, whatever the occasion may be.