I chose this title because I don't want to spoil one thing. So if you aren't through DBZ and don't want to get spoiled, please leave.

Every Sajyan we know that evolved into a Super Sajyan, had some trouble getting there: their rage had to be at a very high level. But there are two exceptions: Goten and Trunks (not the Trunks from the future). How did they get there? They hadn't seen anything that could rage them that much so that they could turn into Super Sajyans.