But Quick had also been harboring his darker dream, police said.
Authorities: The rampage was premeditated
"According to the statement the suspect voluntarily gave investigators, he has had fantasies of stabbing people to death since he was in elementary school," a statement from the Harris County Sheriff's Office said.
Witnesses to the stabbings described a chaotic scene: Bleeding victims collapsed to the ground. Students and teachers ran for cover. Some sprang into action, chasing after the assailant and helping the wounded.
Cassie Foe was in the school's nursing lab when she heard a scream in the hallway.
Moments later, the nursing student put her training into action, placing pressure on a wound in a stabbing victim's neck.
"It just seemed like he was just going around, basically getting whoever was more open and easiest for him to reach," Foe told CNN's Anderson Cooper on Tuesday.
Steven Maida said he saw so many people swarming that he thought it was a campus tour. Then, he saw them running and heard someone say, "My friend's been stabbed."
Maida said he saw blood on a stairway and several injured victims.
"I just took off downstairs running," he said. He was looking for the attacker.
Maida described joining a group of students who chased the suspect, tackled him and pinned him down until authorities arrived.
"I couldn't run the other way like everyone else was," he said.
A bloody spree
Sheriff's Deputy Thomas Gilliland said authorities received an initial report that the suspect had been wrestled to the ground by a student before campus police arrested him.
At least one injured victim had what appeared to be the blade of a box cutter or an X-Acto knife sticking out of her cheek, student Melody Vinton told CNN affiliate KHOU.
Vinton said she had just left her chemistry class when she saw the attacker stabbing people, aiming at their necks and faces.
Soon, she was trying to help victims, ripping a paper towel dispenser off a bathroom wall to get enough paper to help stem the bleeding.
"I turned around, and there was just blood. Just blood dripping down the stairs, all over the floor, all over everyone's towels on their necks. Just a lot of blood," she told KHOU.
Four injured victims "were taken out on helicopters," Harris County sheriff's spokesman Alan Bernstein said.
Tuesday's incident came more than two months after three people were wounded in a shooting at a different Lone Star College campus -- the North Harris campus in Houston.