The interesting thing is that neither of these changes did...
I learned The Settlers of Catan from a college friend of mine, who explained it without glancing at the rules. We had a ball and played most of my senior year. It was only after I’d played some 25-30 games that I bothered to check the rules for myself, and discovered that he had taught us wrong on a couple points. For one thing, he didn’t use the alphabetical order for placing the numbers on the board. We just put out the numbers and tried to break up any adjacent red spots. But the rule that had a much stronger effect was how he taught us to trade: you could trade anything at any time, even when it wasn’t your turn. As you can imagine, this was completely bonkers, especially when we’d get six loud players around the table. Rather than the casual German game that it was, it transformed Catan into Pit with a board.