I'm going to be the "debbie-downer" and say I don't have a pet. We had a dog, but got rid of her when we had our son. I've had a dog my entire life (either at my parents or at my house) and I can say that it is quite liberating getting rid of it. I can say with 80% certainty that I'll never own another pet. It's so much either.
I can understand this statement to a certain point as I love pets but will not have any more due to the fact you are emotionally attached with them....sad to say I had to get my last dog put down to arthritis, witnessing this made me cry.