Yes, exactly, the dangerous dose is not far past the safe dose.

One of the common causes is that many medicines contain Tylenol/acetaminophen, but don't have it in the name [1]. For example, DayQuil or Alka-Seltzer Plus Cold and Sinus.

People take something like that, then they layer Tylenol on top of it thinking that is the first Tylenol they are taking, and it pushes them into the danger zone.

[1] https://www.healthgrades.com/right-care/chronic-pain/5-medic...