Pets are companions that are with you throughout life. That relationship cannot be replaced. As a pet owner myself I have experienced a comfort from a hard day by my pet. To feel loved by my pet is a special feeling that is beyond words. I feel they can detect if I have any discomfort and will do their best to comfort me.
Pets make life easier in some cases. Like if you are obese, your dog can give you motivation to go get up and walk. For me, I have a bearded dragon. It may seem he does not do anything, yet, he makes me extremely happy. He is the only lizard I know that will listen to my problems and not run away. He is the best pet ever.
More importantly he is MY PET!