▁a ura , ▁with ▁a ▁pla int ive ▁harm onica ▁line ▁not ▁dis similar ▁to ▁those ▁heard ▁on ▁En nio ▁Mor ric one ▁sp agh etti ▁western ▁sound tra cks ." ▁ ▁In ▁ 2 0 0 4 , ▁Wilson ▁completed ▁the ▁track ▁for ▁his ▁album ▁Brian ▁Wilson ▁Pres ents ▁Sm ile . ▁This ▁r ere cord ed ▁version ▁incorpor ated ▁an ▁additional ▁set ▁of ▁lyr ics ▁p enn ed ▁by ▁Park s . ▁In ▁ 2 0 1 1 , ▁the ▁Beach ▁Boys ' ▁version ▁was ▁released ▁for ▁the ▁first ▁time ▁as ▁part ▁of ▁The ▁Sm ile ▁S essions ▁box ▁set . ▁ ▁Com position ▁" Child ▁is ▁father ▁of ▁the ▁man " ▁is ▁an ▁id iom ▁origin ating ▁from ▁the ▁poem ▁" My ▁Heart ▁Le aps ▁Up " ▁by ▁William ▁Word sw orth . ▁In ▁a ▁ 1 9 6 6 ▁interview , ▁Wilson ▁mistaken ly ▁attributed ▁it ▁to ▁Karl ▁Men ninger , ▁and ▁added ▁that ▁the ▁saying ▁had ▁fasc in ated ▁him . ▁There ▁exist ▁many ▁different ▁interpret ations ▁of ▁the ▁phrase , ▁the ▁most ▁popular ▁of ▁which ▁is ▁man ▁being ▁the ▁product ▁of ▁hab its ▁and ▁behavior ▁developed ▁in ▁youth . ▁According ▁to ▁collabor ator ▁Van ▁Dy ke ▁Park s , ▁he ▁brought ▁up ▁the ▁id iom ▁to ▁Wilson . ▁ ▁Rec ording ▁Several ▁sections ▁of ▁the ▁song ▁were ▁recorded , ▁but ▁aside ▁from ▁a ▁group ▁piano ▁demo , ▁only ▁one ▁variation ▁of ▁the ▁ch orus ' s ▁backing ▁track ▁was ▁over d ub bed ▁with ▁vocals ▁s ung