[Star Trek TNG] Worfs 'Family Weapon'

Rewatching all of Star Trek in release order. Mid way through TNG Worfs 'Family weapon' that's been 'passed down for generations' seemed very random in S3E26. Seeing as Worf was adopted at age 5 by humans and seemed very disconnected with his Klingon heritage (before Enterprise), it seemed somewhat strange that he found his specific family weapon after everyone on his colony (including his family) was killed. Don't know if they explain in some random episode later, but he either went back to the destroyed colony and found it under the rubble before joining Star Fleet, or he went back to the Klingon empire briefly to retrieve his heirloom, as he was last in line of a noble Klingon family, neither of these are explained (yet?)