Given the practicality and concept based flow features of Accounting, it requires the right amount of interest and focuses to have accounting as a second career. Provided the time is invested in getting behind the concepts and principles of accounting, it is very easy to scale to higher topics. Another perspective is that the whole of the accounting field in its current advanced form started off with simple record/bookkeeping where all the events and transactions were recorded on books. Further came the double-entry system and every other advancement followed. On getting one’s concepts clear, it’s only a couple of steps from there to get an overall picture of the accounting field at large. To advance one’s understanding, you can also take up courses that are online or professional accounting courses such as the Certified Public Accountant, Certified Management Accountant, etc.
It does take a lot of time and interest but I do think it is possible for anyone to take it on as a second career. There are courses online that people can take and a lot of companies now may help pay for someone to go back to school so they can get a degree.