Complicated numbers

i thought that square roots of negative numbers didn't exist. they dont. they're called imaginary numbers. strange concept....IMAGINARY NUMBERS....how do you calculate with them? oh, you cant! the calculations are imaginary! but in my tuition class we managed to manipulate these figments of imagination quite well. ah...higher math.what to say? some of it doesn't quite make sense. today is physics class. i wonder what i'll be exposed to there?