Natan Sharansky told Jewish students in Moscow last week how much has changed in their country since he fought for the rights of Jews in the Soviet Union and spent nine years as a political prisoner.
He entertained the teenage students with tales of how he used a toilet to practice his Hebrew with other Jewish dissidents in prison.
"You take water out of the toilet in your cell, and the other (prisoner) does the same," said Sharansky, now an Israeli politician. "You put your head in and communicate better than with a mobile phone. But it's a lot more dangerous, because if your guard sees you in this unorthodox position what would your explanation be?"
His message at the Lipman Jewish Day School, however, was serious. He described how pleased he was to see a new generation of Russian Jews free to attend Jewish schools and visit Israel.
But hanging over his visit was the persistence of anti-Semitism in Russia today. "There is anti-Semitism in everyday life, and a lot of it," the school's deputy director Irina Sukhalinskya said.
The Soviet government arrested Sharansky in 1977 and accused him of spying for the United States - a charge he said stemmed from his contacts with foreign journalists. He was sentenced to 13 years of hard labor, a plight that cemented his reputation as the most famous Jewish refusenik and political prisoner in the Soviet Union.
Sharansky was freed in 1986 and moved to Israel, where he served in the Knesset and the government.
Now 61, he is continuing his lifelong mission as the new chairman of the Jewish Agency, a quasi-governmental organization that promotes Jewish education and helps Jews immigrate to Israel.
Sharansky praised Russian authorities for combating anti-Semitism and improving ties with Israel.
"When it comes to Jewish history, to Jews' right to be in Israel or to create Jewish communities here, Russian authorities act with tolerance," he said after the lesson. But worrying attitudes remain, he said.
A 2008 poll by the Pew Research Center showed that 34 percent of Russians viewed Jews unfavorably - up from 25 percent in 2004. The research, part of a global survey that involved almost 25,000 respondents in 24 nations, had a margin of error of 3 percent.
Galina Kozhevnikova, deputy director of the Moscow-based Sova hate crimes watchdog, said the level of anti-Semitism is stable and "has not changed in years." The number of attacks on Jews and cases of vandalism against Jewish cemeteries and synagogues is declining, however, she said.