People think perseverance is a feeling, a kind of toughness you either have or you don't. Mostly it's arithmetic. You keep going for as long as you can afford to keep going. So the most practical thing you can do for a dream is make it cheap to stay in.
When I was building Basis, my first startup, I couldn't afford rent. So I slept on friends' couches, sometimes for months at a time, until we raised money. Nobody would recommend it as a plan. But it meant the cost of staying in the game was close to nothing, and when staying costs nothing, you don't have to quit.
Paul Graham, who co-founded Y Combinator, has seen a lot of startups die, and he says they die in one of two ways. "When startups die, the official cause of death is always either running out of money or a critical founder bailing," he wrote in 2007. "Often the two occur simultaneously."
The couch deals with the first cause directly. If you don't need much money to live, it takes much longer to run out of it. Graham has a name for the company version of this. A startup is ramen profitable when it "makes just enough to pay the founders' living expenses," and he says the main importance of that "is that it buys you time." A couch isn't profitable. But it's nearly free, and nearly free buys you time too.
Airbnb's founders found their own version. In 2008 they designed novelty cereal boxes, Obama O's and Cap'n McCain's, and hand-glued the boxes themselves. Brian Chesky later said they made "like $30,000 of collectible breakfast cereal," and that "this is how we funded the company because no other investors gave us money." When they handed Graham a box after their Y Combinator interview, he told them that if they could get people to pay $40 for a $4 box of cereal, maybe they could figure out how to get strangers to live with each other. The cereal didn't prove the business. It proved the founders wouldn't die easily.
That's the second cause, a founder giving up, and the couch doesn't make it go away. Sleeping in someone else's living room can feel like evidence that you've made a mistake. But Graham's advice for that is the most useful line he's written about startups: "Startups rarely die in mid keystroke. So keep typing!"
Which means the real job, most of the time, is just to still be there. Every month you survive is another month for something to work: a customer to say yes, an investor to get it, a feature to click. You can't know which month that will be. You can only make sure you're still in the room when it comes.
There's one more thing the couch teaches, and it's easy to miss. A couch always belongs to someone. Every month I stayed in the game, a friend was carrying a little of the cost. Perseverance looks like a solo act from the outside, but it almost never is. Someone lends you a sofa, a meal, a little faith. The least you can do is make it count.
So if the dream is worth it, don't ask how tough you are. Ask how cheap you can make it to keep going, and then keep typing.