Think of your brain as an engine or computer. Every task uses a certain amount of the brain. well when your brain finds something overwhelming it revs out and can't handle it and breaks out in laughter to keep from revving out of control and blowing up. thus why, when people smoke they tend to laugh alot due to the effects of weed. their thoughts and ideas start racing and once it becomes too much your brain will automatically restrict itself by laughing. Laughing is the rev limiter to the brain...
I don't think he literally means it would blow up, perhaps it's just a metaphor for a complete mental breakdown. I think PrettyCoolGuy has a good point though. Laughter has, and always will be one of our greatest mental defense mechanisms. Laughter evolved from pretty ancient behaviors, and I believe that good humor and laughter have helped humans confront overwhelming situations for a very, very long time. We all cope in different ways, but I think that laughter has always been a healthy reaction to stressful situations, especially since it helps us put it into a context that we can deal with.
exactly! This Idea was actually thought up by myself when i first started smoking. I was completely baked and my brain was running wild with ideas. one of these ideas was my theory here. now as an inside joke with all my smoking buddies is when someone is high and starts cracking up we say they are hitting their rev limiter.