Yeah concussions can be bad.
Example:
During the hockey playoffs, Lombardi took an elbow from Hatcher. He was fine and played in the next 2 or 3 games. After about 5 days, he couldn't play anymore because of his concussion. I don't even know if hes skating yet now, and that was about 10 months ago.
You and Forsberg can hang out:
http://www.tsn.ca/nhl/news_story.asp?id=117891