The info we received when we adopted Pierre was that the owner, a high school boy, came from a single-parent home. He went away to college and couldn't take him, and his mom didn't want the hassle. So yes, there was an aspect of misfortune, but mom could have been more understanding about her son's pet. Or junior could have been more proactive in finding someone else to care for the cat. Whatever the case, we are certainly thankful that Pierre was turned in to the SPCA instead of being cut loose onto the street so that we could give him his "Forever Home".
Our daughter adopted out her cat when she moved away because my wife, her stepmom, is allergic to cats. Rose has to take several prescriptions already, so Sarah didn't want to make her continue the allergy meds in adition to those. When that arrangement fell through, we brought "Aggie" back to our home. Allergy or not (OTC allergy meds are great!), that was one of the best decisions we ever made. Aggie was a joy to have back in our lives for her final 7 or so years. We grew to miss having a pet more and more in the years since Aggie passed away, so we decided that it was time to do something about it.
It's great to be able to just take a lazy day enjoying your family like you could today. Being empty-nesters, we miss those times. Enjoy the heck out of them while you can!