what volunteer work have you take part in? what are reasons for doing voluntary work?

I used to take part in Social work team in my school. They are really dynamic, patient and friendly. They have many activities such as visiting orphanage, joining in taking care children who are affected by dioxin from the Vietnam war, performing mini show from singing, dancing to playacting,... for children in remote areas,... Especially they always attend in many school activites. I feel their enthusiasm, passion and laboriousness and all meaningful and invaluable actions they did. That's why I joined them to contribute my little power to help other people.