every time i smoke i get the giggles. they usually occur early to mid way through the high. i smoke mostly sativa dominant plants. early harvest as well like 20% amber. wether its the weed or me i dont know . but what i do know is that i always laugh when high (especially when im with others) i laugh so much it feels like im going to break a rib or die. i do think it has something to do with your brain because i laugh more than my friends. i guess everyone reacts differently to weed.