Sam Walton is one of the most underappreciated and little known entrepreneurs of all time.
He didn't start Wal Mart until he was 44 years old, and built it from one store to a behemoth multibillion dollar empire.
When he died, his personal fortune, SPLIT 5 WAYS, made all his heirs tied for the richest people in the world. They're still in the top 20 by net worth.
He once spent a night in a Brazilian jail because he was locked up for doing strange things in a store there, measuring the aisles to see how wide they were. They thought he was nuts, so they locked him up. In fact, he was just always studying the competition and was always “on” and willing to dig in and get dirty.
Lesson here is, it's never too late to do something unprecedented, and you can never be too humble. You've got to hustle everyday to do what it takes to succeed.
Here's a great synopsis of his autobiography I found online, give it a skim: