The empty seats at my table are exerting an irresistible force on students. They are dropping into chairs in small groups, ready to have informal meetings. Waves of people are coming to sit at my table; talking and scrabbling in their bags, until one of them innocently lays a laptop on the table.

And then it happens: before the screen is fully open the student in question is firmly reprimanded by a security guard: no laptops at these tables before 2 p.m., they are reserved for lunch. ‘But it shouldn't be news to you, it's written here quite clearly,’ I hear repeatedly. Mumbling, the students creep away, time and again.

I am spared the telling-off - thanks to my age or because I'm doing my correcting on paper - and I watch the spectacle with growing amazement. The similarity in the behavior of the groups of students; this is almost a sequential performance of one and the same choreographed ballet. And most striking of all: this security guard's intransigence.

It must be awful to have to dole out punishment time and again

‘Is it like this all afternoon?’ I dare to ask after a while, as soon as I am sure that I won't be rapped over the knuckles. ‘Yes, every day, all through the lunch period.’ The guard turns out to be a very nice man. ‘Well, that doesn't seem like the most enjoyable aspect of your job,’ I hear myself saying sympathetically. I feel for the guy. It must be awful to have to dole out punishment time and again and to frustrate people's plans. It's enough to make you depressed.

But I could not have been more wrong. ‘What do you mean? I really like doing this,’ the man assures me in amazement. ‘After all, our people also need to be able to have lunch. And the students have to learn to obey the rules. My job here is to teach them some social skills.’ He explains to me that this is the core part of his work, the job that he chose to do decades ago.

I give lectures on the phenomenon of Theory of Mind: the skill of correctly estimating the thoughts, feelings, and intentions of other people. It is a skill that is important in social interaction and something with which people on the autism spectrum, for example, can have difficulty. Theory of Mind - you could almost say that it is my specialist field as a psychologist. But now I am being well and truly taught that I too can be completely wrong. So, after all, I have been rapped over the knuckles.

Yvonne de Kort is Professor of Environmental Psychology at Human-Technology Interaction