I always had this preconception that anything divided by 0 would equal 0.
simple as that.
Zero is about as far from a reasonable answer you can get. As x approaches zero 1/x approaches infinity. Or if you have a negative number it approaches negative infinity. Either of those might be reasonable to think of it if you're not speaking in strictly math laws. In reality a division by zero is undefined. This is because you could easily break all mathematical rules if you attempted to divide by zero. For instance, if x = 0, then this equation holds:
3x = 5x
So we divide by x, and this is what we get left with:
3 = 5
Clearly nonsense, caused by division by zero.