A point in you're life when you realize that smoking weed isn't as cool and exciting as it used to be. It usually takes place when you "hit a wall" in life and you realize you're at that dead end either directly or indirectly because of weed.
John, Mike and Juan - *Smoking*
Ryan comes over to chill.
John: Yo, Ryan you wanna hit this?
Ryan: Nah, I'm good.
Mike: You're crazy!
Ryan: Nah, the shit just gets stale. I hit a weed wall.