A student who witnessed last year’s Florida school massacre has spoken of his anxiety leading up to his return to studies.

Charlie Shebes said he struggled to sleep the night before the first day of his junior year at Marjory Stoneman Douglas High.

He wants to forget what happened but can’t.

Returning to the campus where 17 people were shot to death in the Florida school, he has tried not to relive what happened on February 14 last year.

"I saw bodies on the floor,” he said.

“I saw people on the walls, essentially, and I moved on, because I know it's not going to happen again, so I don't really have to dwell on it aside from the fact that there are reminders everywhere."

Expelled student Nikolas Cruz is accused of opening fire on students and teachers during last year’s massacre.

Lawyers for Cruz have offered a guilty plea in return for a life sentence, but prosecutors are pursuing the death penalty.

Charlie, 16, appreciates the $6.5 million in security improvements, including automatically-locking classroom doors, 17 security monitors, video surveillance and a system to keep out anyone not wearing a school ID.

But he wants school safety and gun control to stay in the national conversation.

"I know the world probably already forgot about us, but I know law enforcement didn't. I guess that's all that matters," he said.

"I just don't want to be forgotten. I feel that's a very common theme when it comes to these kinds of things, is just moving onto the next one, I guess, because it's so common."