The story referenced in the OP ends as follows:
The man replied: ' I don't have an email.'
The broker was dumbfounded. "You don't have an email, and yet have
succeeded in building an empire. Can you imagine what you could have
been if you had an email?," he exclaimed.
The man thought for a while, and replied, "an office boy at
There's a famous short story called THE VERGER (by W. Somerset Maugham), from much earlier in the century (probably the 1930s), whose ending is as follows:
"You see it's like this, sir, I [didn't learn how to read and write]."
The manager stared at him as though he were a prehistoric monster.
"And do you mean to say that you've built up this important business
and amassed a fortune of thirty thousand pounds without being able to
read or write? Good God, man, what would you be now if you had been
"I can tell you that sir," said Mr. Foreman, a little smile on his
still aristocratic features. "I'd be verger of St. Peter's, Neville
The stories seem to me similar, in content (creating a retail business empire), and even in their narrative structure (dialog).
The fact that the latter is famous, earlier, and (presumably) fictional doesn't prove that the later story (referenced in the OP) is also fictional; but I think it's fictional (clearly intended to be allegorical or inspirational), and so I present THE VERGER as 'evidence', and let you be the judge of what you think is probable.
I'll add that various details in the referenced story seem to me improbable (e.g. people buying tomatoes, even for tens of dollars let alone thousands of dollars, which are being sold door-to-door by a stranger at two times their supermarket price) ... but I'm no expert at selling tomatoes.
It's some kind of trope: newspaper boy makes a fortune by selling newspapers, ends up owning the newspaper empire. Here you have the guy owning the supermarket chain.
There are true, real-life stories of people (including poor immigrants) who made a living (if not a fortune) by long, hard work and retail sales; but I don't think this is one of them.