The real Siegfried Sassoon, much like the novel's character, was abandoned by his father early in life. Though he was a decorated soldier, Sassoon declared in 1917 that he no longer agreed with the war. Sent to Craiglockhart, he was treated by the real Dr. Rivers, and there is evidence that he regarded Rivers as a father figure. In his memoir Sherston's Progress, Sassoon refers to Rivers as his "father-confessor." After his stay at the hospital, Sassoon did decide to return to the war in France. He survived and went on to publish many more literary works after the war was over.

In Regeneration, Sassoon the character is an extremely sympathetic figure. He is a man who stands by his convictions and refuses to be used by those who would sacrifice him for their ideals—namely, pacifists. Though Sassoon returns to the war, we do not get the impression that he has been influenced to sacrifice his beliefs. When asked point-blank in the Board meeting about his views toward the war, he replies quite directly that his views have not changed at all. In an environment of madness, Sassoon is sane. His importance is heightened by his individuality.

Though Sassoon holds strong beliefs, he is not foolish in matters of social practice. He believes that homosexuals should be treated with more tolerance, but he sees the practical necessity of remaining silent about his own sexuality. He is a caring and fatherly figure to his troops and to Owen, whom he steers toward a better use of his poetic gifts. Above all, Sassoon, as portrayed in Regeneration, acts as a teacher, guiding those with whom he speaks toward a better knowledge of themselves and of society.