He never listens

My brother does whatever he wants and acts like everyone around him is stupid while he knows everything. He’s a clumsy guy and bought a motor bike and my father and I were against it. Well the other day he got hit by a car on the bike and got hurt and wasn’t wearing protection of course. Thankfully he’s not in critical condition and is home but can’t move around much from being scratched up all over. My father has heart issues and feels sick whenever my brother disrespects him and it hurts me so much. They’re all i have in this world and I don’t know what to do about my brother who is self destructive in everything. He’s 32 and a smart guy but so stupid at the same time… he’s never careful about anything.