Not a genius

Graduation excellence debunked

The multitude of excellent marks on Freud's graduation protocol is suspicious. We don't know whether Freud obtained those marks thanks to academic fraud, forgery, or both, but we know what Freud revealed in his writings about his lack of talent for some of those very subjects. When corresponding with friends, Freud wasn't hiding how he obtained his marks, never imagining that his letters recounting his graduation would ever be made public.
A month after his final exams on July 9, 1873, in a letter of August 6, 1873, Freud revealed to his friend, Eduard Silberstein, that he was "seriously" considering a future as a mathematician. This is how he recounted his considerations,
During the days of my utmost exertions, that is, a week before the now + defunct + matriculation, I earnestly pondered the possibility of creating a system of numbers, having observed that everything in the real world has its equal, or equivalent, in the world of numbers.

Not a mathematic genius

As it is apparent, Freud had given his mathematics ideas a "serious" thought. This is his revelation, Numbers are born, die, marry, and destroy one another like men. In other words, Freud concluded that numbers are sexual creatures observing human customs like marriage and wars. As he explained further, Their estates comprise nobles, soldiers, genealogical tables, just as happens with the estates of mortal man.
There's no doubt that Freud was delusional since he even claimed that, Numbers even have a mythology and gods!
Moreover, already at 17, besides delusion, Freud suffered from megalomania, since he claimed that, though my talent be sparse, my efforts will be praised, and the eternal glory of the idea will be linked with my name, albeit my successors and those who will stand on my shoulders will outshine me in carrying it out. (1)
As a matter of course, this bizarre idea - unlike many others that he hatched during his lifetime - didn't bring him the fame and glory he was dreaming of. But he was nothing if not persistent and in the end, he became the greatest imposter of the 20th century, or maybe ever.

No skills in mathematics

To deal with his lack of mathematical competence, Freud ... in the winter semester of 1876, enrolled in ... three-hour-a-week course, Higher Mathematics for Medical Students. There was a good reason for doing so since, Freud enrolled directly in the Faculty of Medicine, possibly not realising that further skills in mathematics, physics and chemistry were advisable prerequisites for a biomedical research career at the highest level. These were the skills that Freud didn't have.
The course which Freud took, in the Faculty of Medicine, was, tailored to students with morę limited mathematical skills. (2)
More limited sounds like an understatement. Why not say it plainly, the course was for students who, like Freud, his excellent mark notwithstanding, were maths illiterates. And since that was the case, one can only wonder how Freud received an excellent mark in mathematics upon his graduation, most certainly not by honest means.

Impossible science

Thanks to the published letters to his boyfriend in Berlin, we learned that Freud also had difficulties with geometry. Thus, on January 4, 1898, he revealed to Wilhelm Fliess his special problem in this area. I have an infamously low capability for visualizing spatial relationships, Freud wrote, which made the study of geometry and all subjects derived from it impossible for me. (3) .
Freud's mathematical difficulties didn't go away with age. Thus, writing on May 10, 1909 to Oskar Pfister. Freud revealed to him that, Incidentally, it has struck me how difficult it is for us to imagine numbers. (4) Actually, this appears to have been exclusively Freud's own rather than a general problem.
Subsequently, in 1926 Freud confessed to Princess Marie Bonaparte, I have very restricted capacities or talents. None at all of the natural sciences; nothing for mathematics; nothing for anything quantitative. But what I have, of a very restricted nature, was probably very intensive. (5)  Once again, this statement directly contradicts Freud's graduation result, in which he received excellent marks in all of those subjects but one. So what did he have that was very intense? Wouldn't it be, by chance, a propensity for cheating and lying?

Far away stars

Freud didn't learn much physics in high school, either. This is apparent from his letter to his fiancé in which he educated her about the fact (?) that, Astronomers tell us that there are stars ... so far away are they from us and even for rays of light which travel 40,000 miles a second without becoming tired. I always found that hard to imagine. (6) Not for the first time, he was wrong about the numbers. As most people learn in high school, obviously Freud didn't, the speed of light is 186,000 miles (or 300,000 km) per second.

Not an Einstein 

In 1927, Albert Einstein, then 47, visited then 70-year-old Sigmund Freud. Afterward, writing to Ferenczi on January 2, 1927, about their meeting, Freud remarked that Einstein, understands as much about psychology as I do about physics. (7)
So, Freud, the alleged top student in high school, with an excellent mark in physics, had no idea what physics was about. Einstein never studied psychology, but, no doubt, he knew much more about it than Freud knew about physics. After all, aren't we all, to some extent, psychologists?

Poor intellect

As Jones pointed out, Freud, was always sure: that he had a poor intellectual capacity. There were so many things, e.g. in mathematics or physics, he knew he should never be able to understand where so many others could. (8) One can almost feel sorry for the poor Freud - so untalented, and yet so successful - as a fiction writer.
Somehow Jones felt the need to hammer in the fact that Freud was hopeless at mathematics, repeating this claim on several occasions. Thus, again, he pointed out that, mathematics was, a subject where Freud was rather specially deficient. (9) Taking into account, when maths was concerned, Freud's almost limitless limitations, this was a huge understatement.
Further, this is what Jones wrote about Freud's way of working, Of how far removed Freud’s mode of working was [especially in those formative years] from purely intellectual activity such as takes place in much of mathematics and physics one gets a vivid impression from his own descriptions. (10)

Not an expert solver

Jones further clarified his statement, writing that Freud, rather spurned exactitude and precise definition as being either wearisome or pedantic; he could never have been a mathematician or physicist or even an expert solver of chess problems. True, but Freud could instead become a self-professed genius, which is not bad either.
Notably, Jones claimed that even though, Freud had no occasion ever to progress beyond the elements of chemistry and physics, he was without doubt thoroughly familiar with the basic conceptions of these sciences. (11)
It must have been very basic conceptions that Freud was familiar with.
So, how can it be that a totally "unscientific" Freud managed to get the highest marks, in all but one of the subjects, on his graduation? And if it wasn't because he was talented, and not because he studied hard, then how?
(1) Freud, Sigmund, The letters of Sigmund Freud to Eduard Silberstein, 1871-1881, (1990, p. 34).
(2) Schwartz, Joseph, Cassandra's Daughter: A History Of Psychoanalysis, (2006, p. 28).
(3) Freud, Sigmund, he Complete Letters of Sigmund Freud to Wilhelm Fliess, 1887-1904, (1985, p. 292).
(4) Freud, Sigmund, Letters of Sigmund Freud, (1960, p. 280).
(5)  Jones, Sigmund Freud: Life and Work, (1955, p. 443).
(6) Jones, (1953, p. 113).
(7) Ferenczi, S. & Freud, S., The Correspondence of Sigmund Freud and Sandor Ferenczi 1920-1933, (2000, p. 292).
(8) Jones, Ernest, The Life and Work of Sigmund Freud, Edited and Abridged by Lionel Trilling and Steven Marc, (1961, p. 472).
(9) Jones, (1953, p. 303)
(10) Jones, (1953, p. 343).
(11) Jones, (1953, p. 33).