What does getting cerebral contusion mean in the long run?

Don't do it again. Cerebral contusions (bruising) in the brain is usually tolerated okay if it's not too severe. But as each subsequent head injury is cumulative and exponential in it's effects, you only wan this once in your life!
Usually ok. Can bleed, can cause seizures, can leave personality changes and permanent nerve damage. Most of time turns out ok.