Hard disagree. I play single player games wrong all the time! The secret is to make up arbitrary rules the game didn't tell you, and convince yourself these are "the way the game is meant to be played" or "in keeping with the spirit of the game". Then, and this step is very important, you don't enjoy playing the game by these arbitrary rules. Then quit or otherwise lose interest, because breaking your made-up bullshit rules would be akin to hacking the game and cheating at the same time.

Maybe a short example would help: "I have to look in every chest, in every room, and every body. What if one of them contains something special I wouldn't want to have missed", but then that gets old real quick. So I never play it again. It may seem like I exchanged missing one small thing with missing 95% of the game's content, and that may seem like a really dumb thing to do, but in fact I didn't miss that content, it's just on pause in the netherspace, and probably someday maybe I'll return to it.

And on that day I won't have missed a thing. And what a glorious day someday will be...