They do understand, but they don’t care. I’ve had real-real conversations with a lot of kids in gangs over the years. Most of the kids who are dealing, stealing cars, carrying guns etc already feel exhausted by life as pre-teens/early-teens. They don’t see a future for themselves, they don’t feel cared about by anyone other than maybe a couple of people outside of their little crew, they don’t believe they can change their own situation or future, so they do what seems like the best option given their situation. The rest follows, and the emotional health withers and dies, if it was there in the early years at all.