Answer:
Because black mamba is very dangerous and its attack is usually deadly.
Step-by-step explanation:
Black Mamba is one of the most brutal and venomous snakes on the entire African continent. Her attack is often deadly and leaves few survivors. Even the people who survived claim to have suffered so much from the effects of the poison to the point that they felt as if they had been born again when they recovered.
Getting away from the attack of a black mamba is a miracle and represents a new chance for life, as if the individual were also being born once more. It is this new chance that the speaker describes when he says that running away from the black mamba is like being born again.