After the fall of the Persian Empire in 632, Omar, the 2nd successor to the prophet of Islam, issued his legendary order: 'Burn the libraries, for their value is in this book, (i. e., Moslem script).' The result of this decision and its complications was/has been, in fact, tantamount to surgically removing the brains of the Persian scientists of the time. After the burning of the books, Arabs, who had no alphabet of their own, became the absolute rulers of their slaves, the civilized Persians, and their empty dialect, the formal language of half of the world.
Of course, at that time the literate People were the aristocrats and not the peasants. It took the Persians ages to learn their victors' language but it was too late for what they had lost. The decline of Persian mentality and culture has continued to now, as of 632.
To get a better picture one needs to practically transliterate English words in Arabic and measure the time he needs to read the transliterated words. The same calamity happened to all Arab neighbors, as well. These victimized nations have been plunged into darkness and backwardness ever since.
The only shred of luck that the Persians have had was the absence of involvement of the Persian peasants in learning and speaking Arabic. Today the contemporary colloquial Persian language is indebted to the ploughmen of 1400 years ago who were not interested in speaking Arabic. The current colloquial Persian is unique in the world and unyielding to contemporary Arabic-dominated-formal Persian language. It is living side by side the formal Persian. The colloquial dialect is observable in Internet, transliterated by young generation, on their own and without the consent of an Anti-Iranian-Agency, AIA.
It is funny to know that although prayers are in Arabic, the average Persians including the literate tricksters cannot pronounce Arabic words like the Arabs. However, the tricksters, for show off, recite long passages in Arabic to show their divine allegiance to their former masters.
Incidentally, Turkey has been luckier. They, in 1929, formally adopted Latin script instead of the Arabic alphabet. It was apparently meant to increase literacy. In fact, they cut off momentarily the means of communication between the Turks. However, on the other hand, it was a timely blessing by Kemal Atatürk, the father of the modern Turkey, thus emancipating the Turks from the heavy-weight of the shackles of the Arab dominance.
An American who once had been stationed in Turkey as an advisor related the following story:
Turkish translators were ordered to find Turkish equivalents for technical words in a manual. One day a translator encountered the word 'ramjet', a type of jet engine, in the English manual. When the translator failed to find an equivalent, he decided to break down the word 'ramjet' into its components: ram and jet. Next, he translated 'ram', in Turkish, 'male sheep' and 'jet' as 'pissing'. Therefore, it came out as 'pissing male sheep'. It was rejected outright.