Wave particle: 2 people together do not behave as either does alone. For instance, in conversation with someone, one speaker pauses, the other nods, then the first talker goes on. When talking to yourself, you don't pause for the nod from the audience. And if you pause and don't get the nod, it feels as if you are not being listened to.
Social behavior is a wave between the individuals being social with each other, while solitary behavior can be a particle.
Apparently, when I am alone, I cease to exist *to myself* - I can only be *me* in the context of other people.
What my shrink noticed was, as I was describing my day, that I only use the word "I" when with others. When by myself, passive voice gets used a lot, or at least use objects rather than myself as the subject of my verb phrases.
I have always had issues with being ignored, or left out... well, if I don't exist unless attention is being paid to me, by someone else, no wonder.