Numbuh 58 was an agent for only 2 weeks as it took him almost till his 13th birthday to complete basic training.
Having being in the Kids Next Door he wrote himself a dairy to remember all his past missions all three of them. He turned 13 and joined the Teens. He later fought the Kids Next Door on several occasions till he found his old dairy, gave up their destruction, the Teens, was redecomissioned and his dairy destroyed. He then grew up to be an assistant in an accounting business with a terrible tie.