That most insidious form of psychosis which can cause a normally rational person to miss a train and/or miss their station.
It works under the following conditions:
A rational person goes to station with the aim of catching a train to some exotic destination.
They will sit on a bench, and remove some items from a pouch or a briefcase or a handbag such as a paper, a book, food or a personal stereo.
They will then busy themselves with the objects until the train arrives, whereupon they will quickly pack up their things and go to get on the train.
It is at this point when Train Station Psychosis (TSP) kicks in. After having found themselves a seat, the traveller will become convinced that they have left something on the platform and will rush out of the train. The doors will close and the train will go without them, leaving them stranded on the platform, a victim of Train Station Psychosis.
This can also work in reverse: a train draws into a station and a person about to disembark is called back by TSP with the lure of some forgotten item. The train leaves the station and the person will be stuck on board.
It is widely believed that rail companies created TSP in an attempt to increase revenue gained from fines for 'travelling without a sufficient ticket'.