His grandfather, who was active in the resistance to Japanese rule, was wanted by the authorities and had fled to Yenan, where the communists were based in the mainland. When Lin's grandfather left, Lin's grandmother was already pregnant, and when he finally returned from the mainland he discovered that he had a ten-year-old son.
老家在台東關山，林正盛的祖父在日據時代因為抗日被通緝，一度逃到大陸延安「朝聖」，當時祖母已經懷孕，祖父回來時才知道有個十幾歲的兒子。