The other side of the proverbial street comes from the benefits you personally receive by being the loving parent to your companion. I will break these benefits into three categories, and are as follows:
There are two levels of physical benefits, the more obvious being the fact that they force you to get out of the house and be active yourself (specifically related to dogs). By adding multiple walks, runs, and outdoor/fresh air activities into your daily routine you augment the level of physical activity in your life. This increased activity reduces risk of heart disease, lower stress levels, lower cholesterol, as well as lower blood pressure.
By adding another living presence into your life that is completely dependant upon you can aid in your social life. Having a pet can reduce the feeling of loneliness as well as isolation in your home but can also force you to leave the house and interact with other pet owners.
Pets can fulfill emotional needs such as the need for love, companionship, security, mental wellbeing, and comfort. Taking care of and looking after another life that you care about also provides a sense of nurturing and can also be translated into a sense of purpose.
With all this being said this is only the tip of the iceberg in terms of the benefits you receive by choosing to be a loving pet parent!