But in reality, it's just been one year.
On Feb. 14, 2008, Steven Kazmierczak fatally shot five students before turning the gun on himself.
NIU had a day of activities planned for Saturday to mark the anniversary, including a commemoration ceremony, candlelight vigil and memorial wreath laying.
Kazmierczak's victims and their families have found different ways to cope. Some, like Ruiz-Santana, found closure in a visit to the still-closed Cole Hall. Joe Dubowski has left his late daughter Gayle's bedroom just as it was that day. Harold Ng, who was struck in the head by shotgun pellets, has turned to his faith.
"There's an anxiousness," Scott Peska, director of NIU's Office of Support and Advocacy, said of the nearly 25,000-member student body. "The whole campus, they're remembering how they were impacted."
Ruiz-Santana, who previously wanted a career in law enforcement, wants to be a police officer and even interned with the NIU campus police last semester. She wants to help victims of mass shootings and is considering getting a gun license.
"I'm not afraid of guns even after what happened to me," she said.
After Ruiz-Santana was shot, she lay bleeding and gasping for air in the lecture hall aisle. She heard gunshot blasts and saw the gunman's feet walk past her.
"Even when I was there just laying on the floor, it was just so unreal," she said.
Then after a few minutes, the shooting stopped. Later, the authorities arrived.
Ruiz-Santana credits NIU police chief Don Grady with saving her life that Valentine's Day. He held her hand and talked to her to keep her from going into shock.
"He keeps denying it, but I still believe he is my hero," Ruiz-Santana said. "I don't know if I would have been here if it wasn't for him."
It also was Grady who took Ruiz-Santana and her parents into Cole Hall just two months after the shootings. Visiting Cole Hall meant convincing herself that it actually happened, she said, that she survived and had put it behind her.
Grady said he's taken 10 groups of people into Cole Hall this past year.
"I do ask if it's something they're certain they want to do," Grady said. "It's not the easiest thing to go in there."
Walking into Cole Hall brought Ruiz-Santana flashbacks of when Kazmierczak stepped on to the lecture hall's stage and started firing.
"I wanted to go back because I felt that was the way for me to heal completely, emotionally," she said. "Right after I got out of the room I felt like it was over. The doors are closed. Let's move on."
That attitude is why Ruiz-Santana will be successful in whatever she chooses, including police work, Grady said.
"She's refused to let this event define her," Grady said. "She's very grounded and she's very focused."
Ruiz-Santana also has let go of any resentment toward Kazmierczak.
"I was mad and I was really upset and I just wanted to scream from the top of my lungs," she said. "But there's no reason for me to be angry with him if there's nothing I can do about it."
But Joe Dubowski is still angry. His only daughter - Gayle Dubowski, 20, a talented singer and pianist
- was killed in the shootings.
Her family has been in counseling and Joe Dubowski said talking through the grief has helped some, but he's still looking for answers. Kazmierczak left no suicide note and took steps to hide his motive, authorities said.