Need some help

Hello guys! I started reading Haruki Murakami in chronological order and have a question. Sorry if I’m stupid and for my English, but in the end of “hear the wind sing” (action takes place in 1970) author (storyteller) said that he got married, than in pinball 1973 he lives with twins, and than in “a wild sheep chase” (actions take place in 1978) in the beginning of the book it is clear that author is getting divorced and is surprised that the process is easy (that means it is his first divorce probably, but he was married before?). So got kinda confused…