No problem! I confuse myself all the time.
People see all these fancy magazine articles and stories on forums about high compression and pump gas and don't realize it takes lots of experience and money to do it right.
Plus, even when done "right" there's still a very real possibility that it will not like pump gas on certain occasions. Hot outside temps coupled with high humidity sittin in traffic a long time. Or in a truck pulling loads.
People do things without using their own head. If you look back at history, anything over 9:1 compression required premium fuel. And I mean back in the 60s to the early 70s.
One example comes to mind, because a neighbor had it where I grew up as a kid. It was a 1971 LT1 Camaro. 9.2:1. It was totally all original. Had "PREMIUM FUEL ONLY" right on the sun visor and on the gas filler door. Premium fuel. In 1971. That was at or over 100 octane and LEADED.
Would it run on 87? Sure. Until it got good and HOT on a hot day and then it would knock and ping like all hell. Without expensive building techniques like quench or aluminum heads, around 9:1 is indeed the limit on pump gas. Course you can cheat some by running a "big" cam, but then, what's the point? You just lost cylinder pressure. It will be more efficient with 8.5:1 and a matching cam to give optimum cylinder pressure. We are after all talking about a street engine.
No matter how much you talk to some people, they will just not believe an engine can be powerful under 10:1 compression and it just ain't true.