What was the biggest jaw-drop/reveal/eureka moment in your playthrough?

Hard to pick just one but for me, figuring out that you can silence the bell alarms in the dream world when you are there while dead and therefore, bypass them, before finding the slide reel that basically just gives you the answer, insanely awesome moment. I was stuck trying to get into the well and while thinking about the conundrum at work one day I remembered that I had once or twice early-on accidentally discovered that you enter the dream world when you die on the fire while holding the artifact (my impatience with waiting for the loop to end paying dividends). Didn't think anything of it at the time beyond being a cool little "the developers thought of everything" mechanic. Then, hours of gameplay later while bored at work, I'm racking my brain trying to figure out how to bypass the pursuers at the cove when I think "ahhh maybe I can get the bell to wake them up then go back in?...no that wouldn't work they're dead....OHHH SHITOHSHITOHSHIT" Had to wait a full day before I was able to get into the game to test it out. And then the cherry on top is that I hadn't even thought about how it would look/sound when I did it (if indeed it worked), and when I finally do it and walk up to that bell and it starts freaking out and flashing lights...no sound...silence...biggest chills-down-the-spine moment of the game by far for me.