Owning guppies goes something like this:

(Blink) Wow, there's a couple of babies.
(Blink) Wow, there's dozens of babies!
(Blink) OMG, what do I DO with all of these guppies???
(Blink) AAAHHH help me, I have 35 fish tanks full of guppies that I seperated into males and females and they are STILL multiplying!!!!