He was an assistant bookkeeper when he was 16

It is a fact that he was an assistant bookkeeper when he was 16. When Rockefeller was sixteen, he took his first job as an assistant bookkeeper for Hewitt & Tuttle, a small produce commission firm in Cleveland. He worked long hours and was fascinated by all the ways and processes of the workplace, as he subsequently recounted. He was very good at estimating transportation expenses, which came in handy later in his job. Negotiating with barge canal owners, ship captains, and freight agents was a big part of Rockefeller's job. During these conversations, he discovered that listed transportation rates that were thought to be set may be changed based on freight circumstances and scheduling, as well as through the application of rebates to preferred shippers. When Hewitt gave Rockefeller the task of collecting debts, he delegated it to him. Rockefeller depended on constant pestering rather than his father's tactic of presence to collect debts. For his three-month apprenticeship, Rockefeller was paid $16 per month. During his first year, he was paid $31 per month, which was later increased to $50 per month. His final year salary was $58 per month.

Rockefeller reportedly stated as a child that his two major goals in life were to make $100,000 (equal to $2.91 million in 2021 currency) and to live 100 years.