Do you know who Michael is?

At work, Raymond and Steven were chatting:

Raymond: Steven, I have been attending night classes for 5 months now and I have an exam next week.

Steven: oh!

Raymond: For example, do you know who is Graham Bell?

Steven: No

Raymond: He invented the telephone in 1876; if you take night courses you would know this.

The next day, the same discussion took place:

Raymond: Do you know who Alexander Dumas is?

Steven: No

Raymond: He's the author of "The 3 Musketeers", if you take night courses, you would know this.

The next day, once again:

Raymond: And do you know who Jean Jacques Rousseau is?

Steven: No

Raymond: He's the author of "Confessions", if you take night courses, you would know this.

This time, Steven got irritated and said: Do you know who Michael is?

Raymond: No

Steven: He is your neighbor, screwing your wife since five months. If you stop night courses, you would know this.

source: email