They are twins, born on the same day.
The one is stale-grey, whereby every potential action is welcomed with hostility and anger; and the other is more of a suddenly-alert type, where the imagination-led parallel reality is quiet, emptied somehow.
The stale-grey brother cannot take anything less than pure excitement and adventure, and is angry when mundane things cross his path.
The emptied-imagination brother is simply surprised that there is so much hassle around – every detail of the moving surroundings is registered but the fact that the imagination is somehow taking a rest means that those details are left as such. No constant connecting efforts, no search for ever deeper meaning, learning, or explanation.
Probably, the quieted-imagination’s brother’s middle name is Zen.