Gohans courage
Gohans courage stems from his anger and this story will tell you about several occasions when this has happened.
The first time that this had happened was when he had broke out of his make shift prison that was a spaceship pod to save his dad. Radits had his dad cornered and he headbutted his way into his chest. His dad then sacrificed his life to save the earth. Little did they know that the earth would be endangered once again when Raditses boss Vageta came intending to destroy the earth. Before this happened though, Gokus rival, Piccolo had taken Gohan away to train for the proclaimed attack for the next year.
When Vageta came Gohan once again had his time to shine when he turned into a great ape and almost killed Vageta by landing on him in great ape form just before he transformed back into his regular form. Krillin almost killed Vageta when he picked up Yarubis sword and was about to run him through when Goku stopped him saying that he wanted a rematch with him so that he could train hard to beat him.
Another notable time when he had helped out was when he had beaten Cell. Cell had driven hm to rage when he had killed several of the contestants to his tournament and had almost beaten Goku. He transformed into super saiyan 2 and then proceeded to beat cell with a kamehameha wave using only one arm. He then went on to beat Bojack by running him through with his arm and following up with a powerful kamehameha that blew Bojack away. He moved on to his teenage years and then helped to beat Broly for the second time. Gohans courage then went on to beat many new opponents that threatened the earth and he lived to die of ripe old age surrounded y loved ones and friends that would always remember his courage that had saved them all time and time again.