I once had to sit down with a suppliers accountant because the billion dollar company I worked for couldn’t figure out why the PO and the invoices on about 50 orders were slightly off.
Reason: The supplier and billion dollar companies systems used different units of measure. So the conversion created a rounding error as the billion dollar company only went out 4 decimal places This led the the invoices being between $0.01-$0.05 off. All told the difference was $0.01.
It took us 2 hours and I had to buy the suppliers accountant lunch to get it sorted out.
You also had the work/life experience by then to be better able to filter out pertinent information from the material.
Most college textbooks are written in an overly complex manner and require some skill to extract and process the information from them.
So right out of highschool you could have read the textbooks but gotten very little out of them.