Parents typically get two years of investing dollars, calories and so many other resources in them, so that by the time the second born comes along, the firstborn is already ... it's what corporations call "sunk costs," you don't want to disinvest in this one and launch the R&amp;D on the new product.
Roditelji obično daju dvije godine  ulaganja dolara, kalorija i mnogih drugih sredstava u njih, tako da do vremena dok drugorođeni dođe, prvorođeni je već ... ono što  korporacije zovu "potopljeni troškovi," ne želite dezinvestirati u ovome i pokrenuti istraživanje i razvoj na novom proizvodu.