"For a software engineer in Iran, you can find a quite well-paying job [by Iranian standards]. You can get something like 500,000 toumans a month [about $600], but still that [amount of] money is not something that [will give you a comfortable life]. So this was the economic reason. Then I had social reasons to leave Iran. The example I'm telling now is that you couldn't listen to music in your car -- Iranian pop music or I like Turkish pop music. There are many examples of these social restrictions you can think of. [And] there is no freedom of speech."
Garousi says he won't return unless many things change. His story is increasingly typical. Every year more than 150,000 educated young people leave Iran for countries such as the U.S. and Canada. Some 4 million Iranians now live abroad. Few of these will ever return.
Many emigres cite a lack of basic social freedoms. In Iran, boys and girls cannot mingle together in public. Dancing is forbidden. Women and girls must cover their hair and bodies.
Under President Mohammad Khatami there has been a gradual liberalization, but public life is still closely monitored.
The situation is particularly serious among the best-educated young people. As many as four out of five (80 percent) who recently won awards in scientific fields have chosen to emigrate.
Hazhir Rahmandad, who won an international award in chemistry, left Iran in 2000 and now studies at the Massachusetts Institute of Technology in the U.S.
"After finishing my undergraduate studies in industrial engineering, I decided to continue my studies for graduate work, and system dynamics was one of the main areas that [I] was interested in. The only place I could go to was basically the U.S., so that was one of the main reasons. The other thing was that almost everybody was applying [at foreign universities] at the end of [my undergraduate university study]. I was studying at Sharif [University] in Tehran, so it was kind of the norm. And finally I think another dimension of it was that I was interested to see a different world."
Rahmandad says Iran's political structure does not allow people like him to get involved in the country's future as much as they would like to.
"In the short term, I don't think I will be going back," he said. "I actually, personally would really like to go back and be useful to my country and I feel a lot of connection still with whatever is happening in Iran. But on the other hand, I don't see a way of how I can be useful, how I can contribute to building a better Iran -- so it is a challenge."
Amanollah Gharayi Moghadam, a professor of sociology in Tehran, agrees. He says many young people are forced to leave because society cannot absorb them and respond to their needs. "Based on our research, the most important cause for brain drain from Iran is unsuitable social conditions for the youth. There are several factors contributing to this unsuitable atmosphere."
The costs of the brain drain are high. Local sources put the economic loss at some $50 billion a year or higher. "For each inventor or scientist who leaves the country, it is as if 10 oil wells had been destroyed," Moghadam says.
Afshin Molavi is a journalist and author of "Persian Pilgrimages: Journeys Across Iran." Molavi cites economic conditions as a main reason young people choose to leave. The unemployment rate is around 20 percent -- and higher for young people. Hidden in the statistics is massive underemployment, with students forced to take jobs below their qualifications.
"Mostly they describe the economic reasons for leaving the country and they describe simply a lack of jobs, number one, and there is also a massive underemployment problem with young Iranians who may have graduated in, say, engineering ending up working as traders, businessman. Or you might find pharmacists who can't find jobs in their fields so they learn a few software packages and they have to work, say, as a part-time software engineer."
Economists say Iran needs to create more than a million jobs a year just to keep pace with its growing population. In reality, though, only about 300,000 new jobs are added each year.
"It's a very sad thought and quite a tragedy to think that these people who would really like to stay in their home country but they can't simply because of the massive economic mismanagement of the Islamic republic of Iran," Molavi says. "And the irony is that everywhere Iranians go they seem to succeed. It is extraordinary what Iranians are capable of when the are given opportunities, and they are simply not given opportunities in their home country."