Traveling thru the time

This university is located on the premises of what was a psychiatric hospital which was attended by monks and other specialists. Also noteworthy is that the facilities consist of long corridors and a few stairs so it is easier to those unfamiliar with the building  to get confused.
Well, history says that when the process to prepare this hospital to be the ITAM had yet some hospital staff who had their offices still  there, and once, a teacher who was in the facility asked a monk that he found in a corridor kindly tell him how to get to certain offices. The monk took him personally and then invited him to a cup of coffee.

They talked of various matters, but what caught the attention of the teacher was the monk’s theory that time is not a straight line, but it is cyclical, it repeats itself. As one might suppose this theory is not easy to check, so the monk asked the teacher to look for him in his office the next day at 10 am and he could see it by himself.

The next day, very timely for the curiosity of how one could verify this theory, the professor came to where the monk had told him that was his office (on-site ITAM) and asked the secretary for him. The secretary looked at the teacher and called other people working there.

They showed him a photo of the monk, who immediately recognized him as the person who had been talking the day before and right after the secretary handed him a sealed envelope, which according to the secretary, the monk had left 5 years before he dies!, with the instructions that 5 years exactly after his death, a person would come looking for him, and only to this person would be delivered the letter.

The teacher opened the envelope that had only a sheet that had a handwritten statement “My friend, with this I prove you that time is cyclical“