can ▁got ▁the ▁idea ▁for ▁the ▁book ▁while ▁she ▁was ▁making ▁dinner ▁and ▁her ▁daughter ▁Ker ry ▁was ▁having ▁a ▁conversation ▁with ▁a ▁friend ▁in ▁the ▁kitchen . ▁Ker ry ▁told ▁her ▁friend ▁about ▁a ▁boy ▁that ▁interested ▁her , ▁and ▁her ▁friend ▁was ▁considering ▁what ▁to ▁wear ▁on ▁her ▁up coming ▁date . ▁The ▁two ▁eventually ▁found ▁out ▁they ▁were ▁talking ▁about ▁the ▁same ▁boy . ▁Dun can ▁began ▁to ▁wonder ▁what ▁would ▁happen ▁if ▁" the ▁boy ▁had ▁deliber ately ▁impl anted ▁himself ▁in ▁the ▁lives ▁of ▁two ▁girls ▁he ▁knew ▁were ▁friends " ▁and ▁if ▁" he ▁built ▁up ▁a ▁different ▁person ality ▁to ▁present ▁to ▁each ▁of ▁them ". ▁Dun can ▁later ▁read ▁a ▁story ▁about ▁a ▁hit - and - run ▁in ▁the ▁newspaper , ▁which ▁led ▁her ▁to ▁incorpor ate ▁one ▁into ▁the ▁novel . ▁ ▁On ▁October ▁ 5 , ▁ 2 0 1 0 , ▁Little , ▁Brown ▁re iss ued ▁the ▁novel ▁in ▁paper back ▁with ▁updates ▁to ▁modern ize ▁some ▁of ▁the ▁content . ▁I ▁Know ▁What ▁You ▁Did ▁Last ▁Summer ▁was ▁in ▁the ▁first ▁group ▁of ▁ 1 0 ▁different ▁titles ▁that ▁were ▁updated ▁and ▁re iss ued ▁with ▁these ▁changes . ▁In ▁the ▁re vised ▁edition , ▁Dun can ▁gave ▁her ▁characters ▁cell ▁ph ones ▁and ▁updated ▁some ▁of ▁her ▁characters ' ▁cl othing ▁choices . ▁The ▁war ▁Coll ings worth ▁had ▁fought ▁in ▁was ▁changed ▁from ▁the ▁Vietnam ▁War ▁to ▁the ▁Ira q ▁War . ▁ ▁An ▁audio book ,