Why is Shukhov so unconcerned with his day of liberation from the labor camp?

Though Kilgas and the other men joke about the short amount of time left in Shukhov's sentence, he knows better than to hope for it to end. From the experiences of many other men before him, he realizes that release into society and return to his family is far from definite. The Soviet powers may arbitrarily extend his prison sentence or may exile him. Nonetheless, Shukhov cannot always escape the feelings of happiness and excitement that thoughts of the end of his sentence brings. For the most part, these feelings are dangerous to Shukhov and he tries to ignore them, for to expect and envision his release is to court disappointment.