Those of us who are pet owners know that having a dog or cat - or bird, reptile, amphibian, or rodent, depending on your interests - makes life a little bit better. Each breed and individual animal has its quirks, but generally, there is a bond between owner and pet. In the case of dogs and (some) cats, they're waiting when you come home, ready to play, in some cases looking like they're actually smiling because they've been reunited with you after a WHOLE day apart.
Have you ever noticed that being around a pet has a calming effect on your mental and emotional state? Certainly, there are some pets that bring rambunctious energy everywhere they go, but there are others that seem to simply enjoy being nearby. The calming effect of pets is no illusion.