The Fan Theory That Finally Explains Goten And Trunks' Ages In Dragon Ball Super
The sons of Goku and Vegeta are two of the toughest tots this side of the seventh universe. As the half-Saiyan children of the heroes of "Dragon Ball Z," Goten and Trunks were basically born stronger than the majority of their adult peers, and that includes the human Z Fighters. Surely nothing would validate a human-like Krillin, who dedicated his entire life to training and getting stronger, than watching a pair of 10-year-olds completely outclass him by going toe-to-toe with guys like Majin Buu.
Despite all of their strength, however, we actually see very little progression for them once the Buu Saga wrapped up at the end of "DBZ." The sequel series, "Dragon Ball Super," does very little to develop their characters further, and in many ways, it seems as though the makers of "Dragon Ball" are content with leaving them as they are. This is especially odd because while Goten and Trunks have stagnated, time has not. The boys, who should be in their early teens by now, still look like children.
This has been somewhat confusing for fans, who are used to half-Saiyans maturing at a relatively normal rate. Goku, a pure-blood, may have taken a bit longer to fully mature, but his first son Gohan did so at a normal human rate, so it doesn't make much sense for Goten and Trunks to remain child-like for so long. Luckily, fans have developed a theory that explains the inconsistencies in Goten and Trunks' ages in "Dragon Ball Super."
Goten and Trunks messed up their ages in the Hyperbolic Time Chamber
According to a theory fans cooked up on Reddit, it may be possible that Goten and Trunks' ages have stagnated due to the effects of the Hyperbolic Time Chamber. For those who don't know, the Hyperbolic Time Chamber is a magical room located on Kami's Lookout where time passes at a much slower rate on the inside than the outside. In the Cell Saga and Buu Saga of "DBZ," the Z Fighters, including Goten and Trunks, use this room on several occasions to undergo years' worth of training in just a few days.
"Perhaps leaving the time chamber the wrong way does have an effect on aging," wrote u/realraptorjesus101. "But because Buu (well evil Buu) was vaporized, and Piccolo is a god so he will just age pretty slowly anyways, it would kind of make sense?"
Theoretically, this does sound like something that could happen with some light retconning. We also know that the boys used their stint in the Time Chamber to master the Fusion Technique, so perhaps fusing two people into one being while in a magical time-chamber has unintended effects in the "Dragon Ball Super" universe. Unfortunately, nothing like that has been officially confirmed, so for now, the official explanation remains as the boys simply having youthful appearances for their age.