They use to say that about girlfriends (coming from a guys perspective) and I can attest to the fact it works. As far as pets, and once again I speak from experience, wait a few months before getting another ... it gives you time to time to get past the mourning stage and gives you a fresh new outlook when you get your new pet.
Wait, wait....are you saying you went out and bought a new girlfriend?
Isn't that....you know...illegal?...>;)