What makes you think you can handle all the shit that could happen to you in the future?

I was watching “The Diving Bell and the Butterfly”. It’s an amazing true story and this guy gets hit with the most unimaginable tragedy but somehow his will to live is strong enough to get him through all of this hardship.

If you got cancer or were crippled after getting hit by a car or you lost your job and your home and became homeless, do you think you could get through it? Why do you think you have the internal resources to get through hardship? Where does it come from?