When Yasha is sitting on a café in The Magician of Lublin, observing the other patrons (generally well-to-do Poles) it's mentioned that he feels a certain sadness or guilt:
He, Yasha, was to all appearances their equal, yet a barrier separated them. But what was it? He never found a clear explanation. Together with his ambition and lust for life, dwelt a sadness, a sense of the vanity of everything, a guilt that could never be repaid nor forgotten. What was life's purpose if one did not know why one was nor why one died?
(translated by Elaine Gottlieb and Joseph Singer, 1960)
Why does Yasha feel guilty here? Why is it mentioned here in this scene where he's observing the other patrons of the establishment? What is this sadness / guilt?