I'm am retired, and spend much of my time volunteering around the globe with a wonderful organization called World Vets. We get to visit many developing countries, and provide free spay and neuter clinics for local dogs and cats, as well as large animals ,and exotics too ! I get to meet a lot of interesting people, and see places I would not normally visit. In addition to saving the lives of many animals in need, we also help to educate the public about the importance of sterilizing their pets.
I can't think of a better way to spend my retirement !