The Pursuit of Happyness

'Just watched the movie The Pursuit of Happyness again. In general I
find that movie more stressful than uplifting. Scenes of Gardner with
his son in shelters, eating and sleeping there, gets me thinking about
lives other than my own. I cannot fathom what that life must be like,
and I am so grateful to not know of that world from personal
experience.

Chris Gardner  was dirt poor and trying to be a present father for his
son, Christopher. To paraphrase, he was dirt poor and worked his ass
off trying to make it in the stock-brokering world and succeeded (and
then some).

What is the difference between Gardner and the people sitting next to
him and his young son in the shelter dining room?  Is he wired
differently than most, or is Gardner's tenacity fueled by his love for
his son and his focus on wanting to provide for his son?
My question is, how does someone in his scenario (with child or not)
not be tenacious? Meaning, there seems to be people out there who are
actually content with living in the streets, going from shelter to
shelter, eating food from someone else's kitchen and sleeping under a
strange, unfamiliar roof, and I wonder what makes a person this way.
Depression? Complete loss of hope? Laziness?  Yes, there are certainly
cases of mental health issues, and in my opinion, that's a bit
different than other homeless cases.

Perhaps the homeless give-up on the idea that they will ever live a
"normal" life, have their own home, be independent. Perhaps they are
content with sitting on the corner begging for money.
Watching The Pursuit of Happyness, I realized (and maybe this is just
my opinion), that some people just choose to remain on the streets.
And that's what I can't understand. I can't fathom maintaining the
will and strength to move forward until success was achieved as
Gardner did, but then, I can't fathom not doing so either. How could
you possibly stop trying when the option was to sleep in a public
bathroom with your kid on the floor next to you.
Even if you were alone and not with a child, how could you not strive
to get the hell off the streets?
I suppose it's kind-of a useless argument. Perhaps, sadly,
homelessness is something that will never go away.

Kind of like litter bugs.

My apologies for the rambling, but I felt need after watching the
movie and coming across this story...good ol' Jimmy the asshole.
Running into the two drastically contrasting examples triggered it.