What are some reasons why young people joined the red guards

According to a Red Guard leader, the movement's aims were as follows:

Chairman Mao has defined our future as an armed revolutionary youth organization...So if Chairman Mao is our Red-Commander-in-Chief and we are his Red Guards, who can stop us? First we will make China Maoist from inside out and then we will help the working people of other countries make the world red...And then the whole universe.[2]

Despite being met with resistance early on, the Red Guards received personal support from Mao, and the movement rapidly grew. Mao made use of the group as propaganda and to accomplish goals such as destroying symbols of China's pre-communist past, including ancient artifacts and gravesites of notable Chinese figures. However, the government was very permissive of the Red Guards, who were even allowed to inflict bodily harm on people viewed as dissidents. The movement quickly grew out of control, frequently coming into conflict with authority and threatening public security until the government made efforts to rein the youths in. The Red Guard groups also suffered from in-fighting as factions developed among them. By the end of 1968, the group as a formal movement had dissolved.