BTW, this is the passive rule I generally follow:
I'll realize that they're not meant, specifically, to represent passive "always-on" checks in the rules. But that's how I've rolled with them.
I also don't have a hard time with these mechanics at all.
Same here. It always seemed pretty straitforward. Passive Perception sets the variable point at which one notices things without actively searching. It's what you see, hear, smell, etc, while simply "staying alert". It is only a task in the most abstract sense, but it also isn't the same thing as "not paying attention" which would probably be an autofail, or at least disadvantage.
Everyone sees the door. The guy with PP 12 sees that the door is old. The guy with PP 16 sees a bunch of other stuff. All three are just staying alert. The stuff they saw might or might not cause them to look more closely, which would be an active Perception check. They can't get any lower than they would by merely remaining alert, thus PP as a floor.
Okay - the key thing in the section you quoted though is "succeed at something." So they are doing something. I think that's something many people overlook when it comes to passive checks.
Success doesn't necessarily mean actively doing something. You can successfully understand a concept. Recalling a memory isn't really an active task you are undertaking, either, necessarily. It can be, but a lot of times the memory simply triggers upon seeing, smelling, hearing, etc something associated with it.
All sorts of stuff are both passive, on the part of the person "doing" them,
and in question as to whether or not they might succeed.
You may be misunderstanding me. I'm stressing the fact that a passive check resolves a character doing something (successfully or unsuccessfully). A lot of people treat it as a character not doing anything i.e. being passive. But they aren't. They're performing a task.
Unless I'm misunderstanding you.
IMO, paying attention to one's surroundings is only "performing a task" by the most technical definition. On a practical level, especially when discussing a game meant to be read in "natural language", it's a passive stance of sorts. Like standing in a way that doesn't put you at risk of being easily knocked over.
A gust of wind would be ignored by the mechanics if it's not strong enough to feel a push against you, challenge your passive [up to DM] if strong enough to push you a little but not require any active response, and require an active ability check if it was strong enough to require you to respond to it, strengthening or changing your stance.
Similarly,* stuff that requires actively looking around/looking for, requires an active ability check. Depending on what exactly you're doing, it could be Perception or Investigate.
*and no, I don't care about any nit picking about the wording of the specific example. Not saying you will respond that way, just saying, just in case, please don't waste time and space with a derail about the precise nature of an illustrative example that is clearly not the point.