Very amusing but lightweight career memoir by the outstanding Shavian, written just before his death earlier this year, at 82, and published as written. By indirection, Harrison wound up early playing on stage and in film more Shaw than any other playwright, his two outstanding roles being Henry Higgins in My Fair Lady and--in old age, when at last he felt ready for it--the octogenarian Captain Shot-over in Heartbreak House. Among his most amusing moments is the memory of Shaw himself visiting the film studio to watch the production of Major Barbara ""Wendy Hiller and I had got stuck over a terribly high-flown love scene. . .So Wendy and I sat one on each side the elderly Shaw: 'Could you illuminate this scene a little bit for us?' Shaw read through the scene very solemnly, looked rather doleful, and didn't say any. thing for rather a long time. Then he said: 'Ach, what a terrible scene! WHAT a terrible scene!' He hadn't looked at the play since 1913."" Harrison handles his private life lightly indeed, speaks well of his six wives, largely puts his obsession with work down as the chief flaw in his marriages. Even at the end of a run he still reworks his stage business, opens up his roles. And with eight performances weekly requiring a careful harboring of energies, his social life shrinks to nothing--and home life is not much more when a show or a film is in production. He quotes David Garrick: ""Any fool can play tragedy, but comedy, sir, is a damned serious business."" And Edmund Kean, who, when asked on his deathbed if dying was difficult, replied to a young admirer: ""No. Dying is not difficult. But comedy. . .that is difficult!""--all of which Harrison makes marvelously clear regarding Henry Higgins, a show he held back from joining and later found was being written on the road for him personally, with Lerner and Loewe turning out and tossing away song after song. Harrison much preferred the more realistic 25th-anniversary production when he was 75 to his earlier triumph. All work and little play make Rex--and his reader--happy.