It's difficult to have any intuition about scientific things without study. A couple of courses (beyond the freshman level) in chemistry would give you a better grasp of what is meant by isolated systems. Popular writers are very poor at explaining these things (but I'll try anyway, of course.)
There are no true closed systems in the "real world" but one can come close. For example a Dewar flask (the thermos bottle, not the scotch bottle) separates its contents with both a reflective barrier (to keep out radiation) and a vacuum barrier (to keep out matter.) For short times, such a system acts as if it were a closed system (not necessarily true over long time periods; this was a source of some difficulty in the infamous cold fusion experiments.)
A system in a heat bath (like a double boiler but with the working vessel floating) can exchange energy with its surroundings but not matter (if the lid is tight.)
An open system is like a wok.
In various chemistry courses, one gets to work with such systems and develop an intuition for how they differ.
Hello Doc! Thank you ever so much for providing an example of a closed system.
I'm sure it's true that a person lacking intensive scientific studies tends not to develop the intuitive "feel" for things scientific that a working scientist has. This goes without saying. Still it seems that science does not hold the monopoly on intuition.
Mine seemed to be not too off-base on the point in question: that there are no "closed systems" in nature. But then Alamo-Girl wrote to say that the entire Universe is itself a "closed system." And I'm thinking that is quite likely true at the ultimate or principal level. But you can't test that proposition in a laboratory!
Personally, I enjoy mulling over stuff like this. :^)
So please just forgive me for not being a scientist! :^) Given the way my fevered little brain works, philosophy is more "natural" for me. It is my bailywick, the little vineyard I tend for my Lord.
It's good to see you, Doc! Thank you so much for writing.