An event when one suddenly understands something even if the concept had been explained several times before.
Mark had one of those lightbulb moments when he saw the ocean for the first time and realized how huge it was when he couldn't see the other side.
when you have that light bulb appear and get a new idea. Just like in the cartoons you have one your self.
Hey guys I just got an idea; yes I had a light bulb moment!
The light bulb moment is the moment in time when someone comes to the realisation that they are gay.
He had a light bulb moment whilst watching the gay pride parade when he realised that he was just like them.