In the new episode of “Real Cinema,” Vitaly Mansky walks the streets of Riga with writer Alexander Genis — a man who was born and raised here, spent his youth in the city, and whose personality was shaped in many ways by Riga. Their conversation touches on memories of the Soviet 1960s, the Khrushchev Thaw, the book “The Sixties,” co-written with Pyotr Vail, and how literature helped make sense of the past and taught people how to use their freedom. Why did Riga become such a special city for Genis? How did Latvia regain its independence and become part of Europe? And why, despite everything he has lived through, does he remain an optimist?