Feeling disjointed from the world is a rather strange thing to experience.
It's akin to being the one loose wire in a seemingly flawless network, with everyone else locking together and having their own place while you're just sat on the sidelines.
The worst thing about it is that you're often aware of the fact that you're not fitting in, but your head feel so fuzzy and clouded over that you can't do a thing about it.
All you can do is sit and listen to the world passing by, hearing hundreds of voices run together and blend into one mass of noise.
A garbled background track to your own thoughts which seem so much more interesting than whatever is going on around you.
Maybe it's just tiredness, you think, but that doesn't make any sense.
You feel alert enough, but this alertness is in tune to your own personal thoughts rather than clicking onto reality.
The disconnected feeling doesn't come from existing within your own head for a little while, but more the culture shock at coming back to reality.