normal. and then the rest just kind of was what it was. sophomore year was probably the worst for me mental health-wise because i was just recovering from witnessing everything i witnessed, like being in the building. >> reporter: that was the year's brooke's classmate, lauren hog and her family decided they had to leave parkland and move to d.c. >> so much has happened that it feels like i've been living in dog years. >> really? >> it feels like i've been in high school for 20 years. >> reporter: and in those years, they've turned their pain into action. >> i'm 14. i shouldn't have to think about getting shot in my school. >> reporter: starting a movement against gun violence that has gone global with march for our lives, and a crisis that's only gotten worse. there's been more than 150 mass shootings since the beginning of this year. >> mm-hmm. >> and i'm sure my number is low and outdated. >> yeah, it is. >> people are always saying if sandy hook didn't change anything -- you already know what i'm going to say. >> yeah, i know what you're going to say, and for, like, two