I think the biggest mistake of hunter going to Africa for first time is not being informed.
Some are surprised to see fences, when they get there for example.
From that fact, other mistakes happen.
Today we have internet and this forum, good supply of books available on order, and today much easier to get information.
I still see here from time to time, unhappy hunters, but analyzing complaints many times it seams they had wrong expectations.
I wonder how did hunters prepare for their first trip in old days?
Apparently, Roosevelt corresponded to all prominent and relevant African hands of the time, a year in advance, before his famous safari.
But did all first time safari hunters do the same? Very hard to imagine.