Following the incident on The Smiler ride, Leah, 17, had to have a leg amputated, and 18-year-old Joe was left with smashed kneecaps and a damaged hand.
Appearing on ITV's This Morning [8 July], Joe said: "She's still the same person. It's like if you lost a friend just because they changed their hair colour, that's how I thought of it, and if you lose somebody just because they've lost a limb then you're not work having.
"When I went down the other day for an outpatient appointment, we went out for a meal and it felt like nothing had changed."
Despite their determination to live as normally as possible, Joe and Leah's life-changing injuries mean it will be impossible to forget the tragic accident.
He continued: "Obviously then she has to get in a wheelchair and go back to hospital and I have to get on my crutches to go to the toiler or whatever, and it brings it back to you that something has happened."
And brave Joe is already defying doctor's expectations. He added: "They've also said I will struggle travelling more than 40 minutes but yesterday I did three and a half house only stopping once."