Nobody,
That's not an easy question to answer, and as I've grown older I've become more comfortable with leaving such questions unanswered.
I know that must be a bit unsatisfying, so let me explain. When I was younger I was very caught up on defining the edges of things; where "outside" ends and where "inside" begins, for example.
As I grew older I grew less interested in the edges and more interested in the general directions. I think that you and I both have an intuitive idea of what, in our own minds, counts as more "outside" than "inside."
So, I advise people to just figure that out and go that direction. No matter where the edge is, if you keep moving in that direction, at some point you'll cross it anyway, right? And all without having to spell it out in your head, and without having to obsess over the presence of imaginary lines in your internal concepts.
That being said, here's a good rule of thumb; in psychology there is a well known cognitive bias called the "weapon effect."
Simply put, if you put a gun in front of someone's face, they will remember almost everything about the gun, but very little about anything else -- including the face of the person holding the gun.
The gun, because it is threatening them, becomes something we would call a "central" cue. All of the other details are what we would call "peripheral" cues, and one of the well known findings in psychology is that negative emotion causes people to lose track of peripheral cues because they are devoting so much mental energy to processing and remembering central cues.
You're more "outside" of your head when you are easily able to attend to peripheral cues. If you can engage with the details of the world as they are, instead of viewing every bit of incoming information through the lens of your own highly threatening internal conflict, then you're probably on the way "outside."
If someone who was trying to put this in practice, I would advise them to go out, find a quiet place that they would normally overlook, and then take out a pad of paper and make a list of the details they notice in that place.
I tried the experiment myself once, a couple years ago, with an old hotel room. I wrote about it and published the article on Medium. The article was intended to help writers, but it also is just a good introduction to the practice.
J
