you were on the Chunin exams, forest of death, with your team, just trying to survive such hostile place, when you found another team, a team from the Sand Village, conformed by Gaara, Kankuro and Temari, you were scared because you knew what Gaara could do

Gaara: "...You three... Do you want to die?"

Kankuro: "You heard him, out of our way."

Temari: "Unless you are brave enough to fight us."